Classification model trained using Multinomial/Binary Logistic Regression.
Parameters: |
|
---|
>>> data = [
... LabeledPoint(0.0, [0.0, 1.0]),
... LabeledPoint(1.0, [1.0, 0.0]),
... ]
>>> lrm = LogisticRegressionWithSGD.train(sc.parallelize(data), iterations=10)
>>> lrm.predict([1.0, 0.0])
1
>>> lrm.predict([0.0, 1.0])
0
>>> lrm.predict(sc.parallelize([[1.0, 0.0], [0.0, 1.0]])).collect()
[1, 0]
>>> lrm.clearThreshold()
>>> lrm.predict([0.0, 1.0])
0.279...
>>> sparse_data = [
... LabeledPoint(0.0, SparseVector(2, {0: 0.0})),
... LabeledPoint(1.0, SparseVector(2, {1: 1.0})),
... LabeledPoint(0.0, SparseVector(2, {0: 1.0})),
... LabeledPoint(1.0, SparseVector(2, {1: 2.0}))
... ]
>>> lrm = LogisticRegressionWithSGD.train(sc.parallelize(sparse_data), iterations=10)
>>> lrm.predict(array([0.0, 1.0]))
1
>>> lrm.predict(array([1.0, 0.0]))
0
>>> lrm.predict(SparseVector(2, {1: 1.0}))
1
>>> lrm.predict(SparseVector(2, {0: 1.0}))
0
>>> import os, tempfile
>>> path = tempfile.mkdtemp()
>>> lrm.save(sc, path)
>>> sameModel = LogisticRegressionModel.load(sc, path)
>>> sameModel.predict(array([0.0, 1.0]))
1
>>> sameModel.predict(SparseVector(2, {0: 1.0}))
0
>>> from shutil import rmtree
>>> try:
... rmtree(path)
... except:
... pass
>>> multi_class_data = [
... LabeledPoint(0.0, [0.0, 1.0, 0.0]),
... LabeledPoint(1.0, [1.0, 0.0, 0.0]),
... LabeledPoint(2.0, [0.0, 0.0, 1.0])
... ]
>>> data = sc.parallelize(multi_class_data)
>>> mcm = LogisticRegressionWithLBFGS.train(data, iterations=10, numClasses=3)
>>> mcm.predict([0.0, 0.5, 0.0])
0
>>> mcm.predict([0.8, 0.0, 0.0])
1
>>> mcm.predict([0.0, 0.0, 0.3])
2
New in version 0.9.0.
Note
Experimental
Clears the threshold so that predict will output raw prediction scores. It is used for binary classification only.
New in version 1.4.0.
Intercept computed for this model.
New in version 1.0.0.
Number of possible outcomes for k classes classification problem in Multinomial Logistic Regression.
New in version 1.4.0.
Predict values for a single data point or an RDD of points using the model trained.
New in version 0.9.0.
Note
Experimental
Sets the threshold that separates positive predictions from negative predictions. An example with prediction score greater than or equal to this threshold is identified as an positive, and negative otherwise. It is used for binary classification only.
New in version 1.4.0.
Note
Experimental
Returns the threshold (if any) used for converting raw prediction scores into 0/1 predictions. It is used for binary classification only.
New in version 1.4.0.
Weights computed for every feature.
New in version 1.0.0.
New in version 0.9.0.
Train a logistic regression model on the given data.
Parameters: |
|
---|
New in version 0.9.0.
New in version 1.2.0.
Train a logistic regression model on the given data.
Parameters: |
|
---|
>>> data = [
... LabeledPoint(0.0, [0.0, 1.0]),
... LabeledPoint(1.0, [1.0, 0.0]),
... ]
>>> lrm = LogisticRegressionWithLBFGS.train(sc.parallelize(data), iterations=10)
>>> lrm.predict([1.0, 0.0])
1
>>> lrm.predict([0.0, 1.0])
0
New in version 1.2.0.
Model for Support Vector Machines (SVMs).
Parameters: |
|
---|
>>> data = [
... LabeledPoint(0.0, [0.0]),
... LabeledPoint(1.0, [1.0]),
... LabeledPoint(1.0, [2.0]),
... LabeledPoint(1.0, [3.0])
... ]
>>> svm = SVMWithSGD.train(sc.parallelize(data), iterations=10)
>>> svm.predict([1.0])
1
>>> svm.predict(sc.parallelize([[1.0]])).collect()
[1]
>>> svm.clearThreshold()
>>> svm.predict(array([1.0]))
1.44...
>>> sparse_data = [
... LabeledPoint(0.0, SparseVector(2, {0: -1.0})),
... LabeledPoint(1.0, SparseVector(2, {1: 1.0})),
... LabeledPoint(0.0, SparseVector(2, {0: 0.0})),
... LabeledPoint(1.0, SparseVector(2, {1: 2.0}))
... ]
>>> svm = SVMWithSGD.train(sc.parallelize(sparse_data), iterations=10)
>>> svm.predict(SparseVector(2, {1: 1.0}))
1
>>> svm.predict(SparseVector(2, {0: -1.0}))
0
>>> import os, tempfile
>>> path = tempfile.mkdtemp()
>>> svm.save(sc, path)
>>> sameModel = SVMModel.load(sc, path)
>>> sameModel.predict(SparseVector(2, {1: 1.0}))
1
>>> sameModel.predict(SparseVector(2, {0: -1.0}))
0
>>> from shutil import rmtree
>>> try:
... rmtree(path)
... except:
... pass
New in version 0.9.0.
Note
Experimental
Clears the threshold so that predict will output raw prediction scores. It is used for binary classification only.
New in version 1.4.0.
Intercept computed for this model.
New in version 1.0.0.
Predict values for a single data point or an RDD of points using the model trained.
New in version 0.9.0.
Note
Experimental
Sets the threshold that separates positive predictions from negative predictions. An example with prediction score greater than or equal to this threshold is identified as an positive, and negative otherwise. It is used for binary classification only.
New in version 1.4.0.
Note
Experimental
Returns the threshold (if any) used for converting raw prediction scores into 0/1 predictions. It is used for binary classification only.
New in version 1.4.0.
Weights computed for every feature.
New in version 1.0.0.
New in version 0.9.0.
Train a support vector machine on the given data.
Parameters: |
|
---|
New in version 0.9.0.
Model for Naive Bayes classifiers.
Parameters: |
|
---|
>>> data = [
... LabeledPoint(0.0, [0.0, 0.0]),
... LabeledPoint(0.0, [0.0, 1.0]),
... LabeledPoint(1.0, [1.0, 0.0]),
... ]
>>> model = NaiveBayes.train(sc.parallelize(data))
>>> model.predict(array([0.0, 1.0]))
0.0
>>> model.predict(array([1.0, 0.0]))
1.0
>>> model.predict(sc.parallelize([[1.0, 0.0]])).collect()
[1.0]
>>> sparse_data = [
... LabeledPoint(0.0, SparseVector(2, {1: 0.0})),
... LabeledPoint(0.0, SparseVector(2, {1: 1.0})),
... LabeledPoint(1.0, SparseVector(2, {0: 1.0}))
... ]
>>> model = NaiveBayes.train(sc.parallelize(sparse_data))
>>> model.predict(SparseVector(2, {1: 1.0}))
0.0
>>> model.predict(SparseVector(2, {0: 1.0}))
1.0
>>> import os, tempfile
>>> path = tempfile.mkdtemp()
>>> model.save(sc, path)
>>> sameModel = NaiveBayesModel.load(sc, path)
>>> sameModel.predict(SparseVector(2, {0: 1.0})) == model.predict(SparseVector(2, {0: 1.0}))
True
>>> from shutil import rmtree
>>> try:
... rmtree(path)
... except OSError:
... pass
New in version 0.9.0.
New in version 0.9.0.
Train a Naive Bayes model given an RDD of (label, features) vectors.
This is the Multinomial NB (U{http://tinyurl.com/lsdw6p}) which can handle all kinds of discrete data. For example, by converting documents into TF-IDF vectors, it can be used for document classification. By making every vector a 0-1 vector, it can also be used as Bernoulli NB (U{http://tinyurl.com/p7c96j6}). The input feature values must be nonnegative.
Parameters: |
|
---|
New in version 0.9.0.
Train or predict a logistic regression model on streaming data. Training uses Stochastic Gradient Descent to update the model based on each new batch of incoming data from a DStream.
Each batch of data is assumed to be an RDD of LabeledPoints. The number of data points per batch can vary, but the number of features must be constant. An initial weight vector must be provided.
Parameters: |
|
---|
New in version 1.5.0.
Returns the latest model.
New in version 1.5.0.
Make predictions on a dstream.
Returns: | Transformed dstream object. |
---|
New in version 1.5.0.
Make predictions on a keyed dstream.
Returns: | Transformed dstream object. |
---|
New in version 1.5.0.
A clustering model derived from the k-means method.
>>> data = array([0.0,0.0, 1.0,1.0, 9.0,8.0, 8.0,9.0]).reshape(4, 2)
>>> model = KMeans.train(
... sc.parallelize(data), 2, maxIterations=10, runs=30, initializationMode="random",
... seed=50, initializationSteps=5, epsilon=1e-4)
>>> model.predict(array([0.0, 0.0])) == model.predict(array([1.0, 1.0]))
True
>>> model.predict(array([8.0, 9.0])) == model.predict(array([9.0, 8.0]))
True
>>> model.k
2
>>> model.computeCost(sc.parallelize(data))
2.0000000000000004
>>> model = KMeans.train(sc.parallelize(data), 2)
>>> sparse_data = [
... SparseVector(3, {1: 1.0}),
... SparseVector(3, {1: 1.1}),
... SparseVector(3, {2: 1.0}),
... SparseVector(3, {2: 1.1})
... ]
>>> model = KMeans.train(sc.parallelize(sparse_data), 2, initializationMode="k-means||",
... seed=50, initializationSteps=5, epsilon=1e-4)
>>> model.predict(array([0., 1., 0.])) == model.predict(array([0, 1.1, 0.]))
True
>>> model.predict(array([0., 0., 1.])) == model.predict(array([0, 0, 1.1]))
True
>>> model.predict(sparse_data[0]) == model.predict(sparse_data[1])
True
>>> model.predict(sparse_data[2]) == model.predict(sparse_data[3])
True
>>> isinstance(model.clusterCenters, list)
True
>>> import os, tempfile
>>> path = tempfile.mkdtemp()
>>> model.save(sc, path)
>>> sameModel = KMeansModel.load(sc, path)
>>> sameModel.predict(sparse_data[0]) == model.predict(sparse_data[0])
True
>>> from shutil import rmtree
>>> try:
... rmtree(path)
... except OSError:
... pass
>>> data = array([-383.1,-382.9, 28.7,31.2, 366.2,367.3]).reshape(3, 2)
>>> model = KMeans.train(sc.parallelize(data), 3, maxIterations=0,
... initialModel = KMeansModel([(-1000.0,-1000.0),(5.0,5.0),(1000.0,1000.0)]))
>>> model.clusterCenters
[array([-1000., -1000.]), array([ 5., 5.]), array([ 1000., 1000.])]
New in version 0.9.0.
Get the cluster centers, represented as a list of NumPy arrays.
New in version 1.0.0.
Note
Experimental
A clustering model derived from the Gaussian Mixture Model method.
>>> from pyspark.mllib.linalg import Vectors, DenseMatrix
>>> from numpy.testing import assert_equal
>>> from shutil import rmtree
>>> import os, tempfile
>>> clusterdata_1 = sc.parallelize(array([-0.1,-0.05,-0.01,-0.1,
... 0.9,0.8,0.75,0.935,
... -0.83,-0.68,-0.91,-0.76 ]).reshape(6, 2))
>>> model = GaussianMixture.train(clusterdata_1, 3, convergenceTol=0.0001,
... maxIterations=50, seed=10)
>>> labels = model.predict(clusterdata_1).collect()
>>> labels[0]==labels[1]
False
>>> labels[1]==labels[2]
True
>>> labels[4]==labels[5]
True
>>> path = tempfile.mkdtemp()
>>> model.save(sc, path)
>>> sameModel = GaussianMixtureModel.load(sc, path)
>>> assert_equal(model.weights, sameModel.weights)
>>> mus, sigmas = list(
... zip(*[(g.mu, g.sigma) for g in model.gaussians]))
>>> sameMus, sameSigmas = list(
... zip(*[(g.mu, g.sigma) for g in sameModel.gaussians]))
>>> mus == sameMus
True
>>> sigmas == sameSigmas
True
>>> from shutil import rmtree
>>> try:
... rmtree(path)
... except OSError:
... pass
>>> data = array([-5.1971, -2.5359, -3.8220,
... -5.2211, -5.0602, 4.7118,
... 6.8989, 3.4592, 4.6322,
... 5.7048, 4.6567, 5.5026,
... 4.5605, 5.2043, 6.2734])
>>> clusterdata_2 = sc.parallelize(data.reshape(5,3))
>>> model = GaussianMixture.train(clusterdata_2, 2, convergenceTol=0.0001,
... maxIterations=150, seed=10)
>>> labels = model.predict(clusterdata_2).collect()
>>> labels[0]==labels[1]
True
>>> labels[2]==labels[3]==labels[4]
True
New in version 1.3.0.
Array of MultivariateGaussian where gaussians[i] represents the Multivariate Gaussian (Normal) Distribution for Gaussian i.
New in version 1.4.0.
Load the GaussianMixtureModel from disk.
Parameters: |
|
---|
New in version 1.5.0.
Find the cluster to which the points in ‘x’ has maximum membership in this model.
Parameters: | x – RDD of data points. |
---|---|
Returns: | cluster_labels. RDD of cluster labels. |
New in version 1.3.0.
Note
Experimental
Learning algorithm for Gaussian Mixtures using the expectation-maximization algorithm.
Parameters: |
|
---|
New in version 1.3.0.
Note
Experimental
Model produced by [[PowerIterationClustering]].
>>> import math
>>> def genCircle(r, n):
... points = []
... for i in range(0, n):
... theta = 2.0 * math.pi * i / n
... points.append((r * math.cos(theta), r * math.sin(theta)))
... return points
>>> def sim(x, y):
... dist2 = (x[0] - y[0]) * (x[0] - y[0]) + (x[1] - y[1]) * (x[1] - y[1])
... return math.exp(-dist2 / 2.0)
>>> r1 = 1.0
>>> n1 = 10
>>> r2 = 4.0
>>> n2 = 40
>>> n = n1 + n2
>>> points = genCircle(r1, n1) + genCircle(r2, n2)
>>> similarities = [(i, j, sim(points[i], points[j])) for i in range(1, n) for j in range(0, i)]
>>> rdd = sc.parallelize(similarities, 2)
>>> model = PowerIterationClustering.train(rdd, 2, 40)
>>> model.k
2
>>> result = sorted(model.assignments().collect(), key=lambda x: x.id)
>>> result[0].cluster == result[1].cluster == result[2].cluster == result[3].cluster
True
>>> result[4].cluster == result[5].cluster == result[6].cluster == result[7].cluster
True
>>> import os, tempfile
>>> path = tempfile.mkdtemp()
>>> model.save(sc, path)
>>> sameModel = PowerIterationClusteringModel.load(sc, path)
>>> sameModel.k
2
>>> result = sorted(model.assignments().collect(), key=lambda x: x.id)
>>> result[0].cluster == result[1].cluster == result[2].cluster == result[3].cluster
True
>>> result[4].cluster == result[5].cluster == result[6].cluster == result[7].cluster
True
>>> from shutil import rmtree
>>> try:
... rmtree(path)
... except OSError:
... pass
New in version 1.5.0.
Note
Experimental
Power Iteration Clustering (PIC), a scalable graph clustering algorithm developed by [[http://www.icml2010.org/papers/387.pdf Lin and Cohen]]. From the abstract: PIC finds a very low-dimensional embedding of a dataset using truncated power iteration on a normalized pair-wise similarity matrix of the data.
New in version 1.5.0.
Parameters: |
|
---|
New in version 1.5.0.
Note
Experimental
Provides methods to set k, decayFactor, timeUnit to configure the KMeans algorithm for fitting and predicting on incoming dstreams. More details on how the centroids are updated are provided under the docs of StreamingKMeansModel.
Parameters: |
|
---|
New in version 1.5.0.
Make predictions on a dstream. Returns a transformed dstream object
New in version 1.5.0.
Make predictions on a keyed dstream. Returns a transformed dstream object.
New in version 1.5.0.
Set number of batches after which the centroids of that particular batch has half the weightage.
New in version 1.5.0.
Set initial centers. Should be set before calling trainOn.
New in version 1.5.0.
Note
Experimental
Clustering model which can perform an online update of the centroids.
The update formula for each centroid is given by
where
c_t: Centroid at the n_th iteration.
at the n_th iteration.
x_t: Centroid of the new data closest to c_t.
m_t: Number of samples (or) weights of the new data closest to c_t
c_t+1: New centroid.
n_t+1: New number of weights.
a: Decay Factor, which gives the forgetfulness.
Note that if a is set to 1, it is the weighted mean of the previous and new data. If it set to zero, the old centroids are completely forgotten.
Parameters: |
|
---|
>>> initCenters = [[0.0, 0.0], [1.0, 1.0]]
>>> initWeights = [1.0, 1.0]
>>> stkm = StreamingKMeansModel(initCenters, initWeights)
>>> data = sc.parallelize([[-0.1, -0.1], [0.1, 0.1],
... [0.9, 0.9], [1.1, 1.1]])
>>> stkm = stkm.update(data, 1.0, u"batches")
>>> stkm.centers
array([[ 0., 0.],
[ 1., 1.]])
>>> stkm.predict([-0.1, -0.1])
0
>>> stkm.predict([0.9, 0.9])
1
>>> stkm.clusterWeights
[3.0, 3.0]
>>> decayFactor = 0.0
>>> data = sc.parallelize([DenseVector([1.5, 1.5]), DenseVector([0.2, 0.2])])
>>> stkm = stkm.update(data, 0.0, u"batches")
>>> stkm.centers
array([[ 0.2, 0.2],
[ 1.5, 1.5]])
>>> stkm.clusterWeights
[1.0, 1.0]
>>> stkm.predict([0.2, 0.2])
0
>>> stkm.predict([1.5, 1.5])
1
New in version 1.5.0.
Update the centroids, according to data
Parameters: |
|
---|
New in version 1.5.0.
New in version 1.5.0.
Train a LDA model.
Parameters: |
|
---|
New in version 1.5.0.
A clustering model derived from the LDA method.
Latent Dirichlet Allocation (LDA), a topic model designed for text documents. Terminology - “word” = “term”: an element of the vocabulary - “token”: instance of a term appearing in a document - “topic”: multinomial distribution over words representing some concept References: - Original LDA paper (journal version): Blei, Ng, and Jordan. “Latent Dirichlet Allocation.” JMLR, 2003.
>>> from pyspark.mllib.linalg import Vectors
>>> from numpy.testing import assert_almost_equal, assert_equal
>>> data = [
... [1, Vectors.dense([0.0, 1.0])],
... [2, SparseVector(2, {0: 1.0})],
... ]
>>> rdd = sc.parallelize(data)
>>> model = LDA.train(rdd, k=2, seed=1)
>>> model.vocabSize()
2
>>> model.describeTopics()
[([1, 0], [0.5..., 0.49...]), ([0, 1], [0.5..., 0.49...])]
>>> model.describeTopics(1)
[([1], [0.5...]), ([0], [0.5...])]
>>> topics = model.topicsMatrix()
>>> topics_expect = array([[0.5, 0.5], [0.5, 0.5]])
>>> assert_almost_equal(topics, topics_expect, 1)
>>> import os, tempfile
>>> from shutil import rmtree
>>> path = tempfile.mkdtemp()
>>> model.save(sc, path)
>>> sameModel = LDAModel.load(sc, path)
>>> assert_equal(sameModel.topicsMatrix(), model.topicsMatrix())
>>> sameModel.vocabSize() == model.vocabSize()
True
>>> try:
... rmtree(path)
... except OSError:
... pass
New in version 1.5.0.
Return the topics described by weighted terms.
WARNING: If vocabSize and k are large, this can return a large object!
Parameters: | maxTermsPerTopic – Maximum number of terms to collect for each topic. (default: vocabulary size) |
---|---|
Returns: | Array over topics. Each topic is represented as a pair of matching arrays: (term indices, term weights in topic). Each topic’s terms are sorted in order of decreasing weight. |
New in version 1.6.0.
Load the LDAModel from disk.
Parameters: |
|
---|
New in version 1.5.0.
Evaluator for binary classification.
Parameters: | scoreAndLabels – an RDD of (score, label) pairs |
---|
>>> scoreAndLabels = sc.parallelize([
... (0.1, 0.0), (0.1, 1.0), (0.4, 0.0), (0.6, 0.0), (0.6, 1.0), (0.6, 1.0), (0.8, 1.0)], 2)
>>> metrics = BinaryClassificationMetrics(scoreAndLabels)
>>> metrics.areaUnderROC
0.70...
>>> metrics.areaUnderPR
0.83...
>>> metrics.unpersist()
New in version 1.4.0.
Evaluator for regression.
Parameters: | predictionAndObservations – an RDD of (prediction, observation) pairs. |
---|
>>> predictionAndObservations = sc.parallelize([
... (2.5, 3.0), (0.0, -0.5), (2.0, 2.0), (8.0, 7.0)])
>>> metrics = RegressionMetrics(predictionAndObservations)
>>> metrics.explainedVariance
8.859...
>>> metrics.meanAbsoluteError
0.5...
>>> metrics.meanSquaredError
0.37...
>>> metrics.rootMeanSquaredError
0.61...
>>> metrics.r2
0.94...
New in version 1.4.0.
Returns the explained variance regression score. explainedVariance = 1 - variance(y - hat{y}) / variance(y)
New in version 1.4.0.
Returns the mean absolute error, which is a risk function corresponding to the expected value of the absolute error loss or l1-norm loss.
New in version 1.4.0.
Evaluator for multiclass classification.
Parameters: | predictionAndLabels – an RDD of (prediction, label) pairs. |
---|
>>> predictionAndLabels = sc.parallelize([(0.0, 0.0), (0.0, 1.0), (0.0, 0.0),
... (1.0, 0.0), (1.0, 1.0), (1.0, 1.0), (1.0, 1.0), (2.0, 2.0), (2.0, 0.0)])
>>> metrics = MulticlassMetrics(predictionAndLabels)
>>> metrics.confusionMatrix().toArray()
array([[ 2., 1., 1.],
[ 1., 3., 0.],
[ 0., 0., 1.]])
>>> metrics.falsePositiveRate(0.0)
0.2...
>>> metrics.precision(1.0)
0.75...
>>> metrics.recall(2.0)
1.0...
>>> metrics.fMeasure(0.0, 2.0)
0.52...
>>> metrics.precision()
0.66...
>>> metrics.recall()
0.66...
>>> metrics.weightedFalsePositiveRate
0.19...
>>> metrics.weightedPrecision
0.68...
>>> metrics.weightedRecall
0.66...
>>> metrics.weightedFMeasure()
0.66...
>>> metrics.weightedFMeasure(2.0)
0.65...
New in version 1.4.0.
Returns confusion matrix: predicted classes are in columns, they are ordered by class label ascending, as in “labels”.
New in version 1.4.0.
Returns f-measure or f-measure for a given label (category) if specified.
New in version 1.4.0.
Returns false positive rate for a given label (category).
New in version 1.4.0.
Returns precision or precision for a given label (category) if specified.
New in version 1.4.0.
Returns recall or recall for a given label (category) if specified.
New in version 1.4.0.
Returns true positive rate for a given label (category).
New in version 1.4.0.
Evaluator for ranking algorithms.
Parameters: | predictionAndLabels – an RDD of (predicted ranking, ground truth set) pairs. |
---|
>>> predictionAndLabels = sc.parallelize([
... ([1, 6, 2, 7, 8, 3, 9, 10, 4, 5], [1, 2, 3, 4, 5]),
... ([4, 1, 5, 6, 2, 7, 3, 8, 9, 10], [1, 2, 3]),
... ([1, 2, 3, 4, 5], [])])
>>> metrics = RankingMetrics(predictionAndLabels)
>>> metrics.precisionAt(1)
0.33...
>>> metrics.precisionAt(5)
0.26...
>>> metrics.precisionAt(15)
0.17...
>>> metrics.meanAveragePrecision
0.35...
>>> metrics.ndcgAt(3)
0.33...
>>> metrics.ndcgAt(10)
0.48...
New in version 1.4.0.
Returns the mean average precision (MAP) of all the queries. If a query has an empty ground truth set, the average precision will be zero and a log warining is generated.
New in version 1.4.0.
Compute the average NDCG value of all the queries, truncated at ranking position k. The discounted cumulative gain at position k is computed as: sum,,i=1,,^k^ (2^{relevance of ‘’i’‘th item}^ - 1) / log(i + 1), and the NDCG is obtained by dividing the DCG value on the ground truth set. In the current implementation, the relevance value is binary. If a query has an empty ground truth set, zero will be used as NDCG together with a log warning.
New in version 1.4.0.
Compute the average precision of all the queries, truncated at ranking position k.
If for a query, the ranking algorithm returns n (n < k) results, the precision value will be computed as #(relevant items retrieved) / k. This formula also applies when the size of the ground truth set is less than k.
If a query has an empty ground truth set, zero will be used as precision together with a log warning.
New in version 1.4.0.
Python package for feature in MLlib.
Bases: pyspark.mllib.feature.VectorTransformer
Note
Experimental
Normalizes samples individually to unit Lp norm
For any 1 <= p < float(‘inf’), normalizes samples using sum(abs(vector) p) (1/p) as norm.
For p = float(‘inf’), max(abs(vector)) will be used as norm for normalization.
Parameters: | p – Normalization in L^p^ space, p = 2 by default. |
---|
>>> v = Vectors.dense(range(3))
>>> nor = Normalizer(1)
>>> nor.transform(v)
DenseVector([0.0, 0.3333, 0.6667])
>>> rdd = sc.parallelize([v])
>>> nor.transform(rdd).collect()
[DenseVector([0.0, 0.3333, 0.6667])]
>>> nor2 = Normalizer(float("inf"))
>>> nor2.transform(v)
DenseVector([0.0, 0.5, 1.0])
New in version 1.2.0.
Bases: pyspark.mllib.feature.JavaVectorTransformer
Note
Experimental
Represents a StandardScaler model that can transform vectors.
New in version 1.2.0.
Setter of the boolean which decides whether it uses mean or not
New in version 1.4.0.
Setter of the boolean which decides whether it uses std or not
New in version 1.4.0.
Applies standardization transformation on a vector.
Parameters: | vector – Vector or RDD of Vector to be standardized. |
---|---|
Returns: | Standardized vector. If the variance of a column is zero, it will return default 0.0 for the column with zero variance. |
New in version 1.2.0.
Bases: object
Note
Experimental
Standardizes features by removing the mean and scaling to unit variance using column summary statistics on the samples in the training set.
Parameters: |
|
---|
>>> vs = [Vectors.dense([-2.0, 2.3, 0]), Vectors.dense([3.8, 0.0, 1.9])]
>>> dataset = sc.parallelize(vs)
>>> standardizer = StandardScaler(True, True)
>>> model = standardizer.fit(dataset)
>>> result = model.transform(dataset)
>>> for r in result.collect(): r
DenseVector([-0.7071, 0.7071, -0.7071])
DenseVector([0.7071, -0.7071, 0.7071])
New in version 1.2.0.
Bases: object
Note
Experimental
Maps a sequence of terms to their term frequencies using the hashing trick.
Note: the terms must be hashable (can not be dict/set/list...).
Parameters: | numFeatures – number of features (default: 2^20) |
---|
>>> htf = HashingTF(100)
>>> doc = "a a b b c d".split(" ")
>>> htf.transform(doc)
SparseVector(100, {...})
New in version 1.2.0.
Bases: pyspark.mllib.feature.JavaVectorTransformer
Represents an IDF model that can transform term frequency vectors.
New in version 1.2.0.
Transforms term frequency (TF) vectors to TF-IDF vectors.
If minDocFreq was set for the IDF calculation, the terms which occur in fewer than minDocFreq documents will have an entry of 0.
Parameters: | x – an RDD of term frequency vectors or a term frequency vector |
---|---|
Returns: | an RDD of TF-IDF vectors or a TF-IDF vector |
New in version 1.2.0.
Bases: object
Note
Experimental
Inverse document frequency (IDF).
The standard formulation is used: idf = log((m + 1) / (d(t) + 1)), where m is the total number of documents and d(t) is the number of documents that contain term t.
This implementation supports filtering out terms which do not appear in a minimum number of documents (controlled by the variable minDocFreq). For terms that are not in at least minDocFreq documents, the IDF is found as 0, resulting in TF-IDFs of 0.
Parameters: | minDocFreq – minimum of documents in which a term should appear for filtering |
---|
>>> n = 4
>>> freqs = [Vectors.sparse(n, (1, 3), (1.0, 2.0)),
... Vectors.dense([0.0, 1.0, 2.0, 3.0]),
... Vectors.sparse(n, [1], [1.0])]
>>> data = sc.parallelize(freqs)
>>> idf = IDF()
>>> model = idf.fit(data)
>>> tfidf = model.transform(data)
>>> for r in tfidf.collect(): r
SparseVector(4, {1: 0.0, 3: 0.5754})
DenseVector([0.0, 0.0, 1.3863, 0.863])
SparseVector(4, {1: 0.0})
>>> model.transform(Vectors.dense([0.0, 1.0, 2.0, 3.0]))
DenseVector([0.0, 0.0, 1.3863, 0.863])
>>> model.transform([0.0, 1.0, 2.0, 3.0])
DenseVector([0.0, 0.0, 1.3863, 0.863])
>>> model.transform(Vectors.sparse(n, (1, 3), (1.0, 2.0)))
SparseVector(4, {1: 0.0, 3: 0.5754})
New in version 1.2.0.
Bases: object
Word2Vec creates vector representation of words in a text corpus. The algorithm first constructs a vocabulary from the corpus and then learns vector representation of words in the vocabulary. The vector representation can be used as features in natural language processing and machine learning algorithms.
We used skip-gram model in our implementation and hierarchical softmax method to train the model. The variable names in the implementation matches the original C implementation.
For original C implementation, see https://code.google.com/p/word2vec/ For research papers, see Efficient Estimation of Word Representations in Vector Space and Distributed Representations of Words and Phrases and their Compositionality.
>>> sentence = "a b " * 100 + "a c " * 10
>>> localDoc = [sentence, sentence]
>>> doc = sc.parallelize(localDoc).map(lambda line: line.split(" "))
>>> model = Word2Vec().setVectorSize(10).setSeed(42).fit(doc)
>>> syms = model.findSynonyms("a", 2)
>>> [s[0] for s in syms]
[u'b', u'c']
>>> vec = model.transform("a")
>>> syms = model.findSynonyms(vec, 2)
>>> [s[0] for s in syms]
[u'b', u'c']
>>> import os, tempfile
>>> path = tempfile.mkdtemp()
>>> model.save(sc, path)
>>> sameModel = Word2VecModel.load(sc, path)
>>> model.transform("a") == sameModel.transform("a")
True
>>> syms = sameModel.findSynonyms("a", 2)
>>> [s[0] for s in syms]
[u'b', u'c']
>>> from shutil import rmtree
>>> try:
... rmtree(path)
... except OSError:
... pass
New in version 1.2.0.
Computes the vector representation of each word in vocabulary.
Parameters: | data – training data. RDD of list of string |
---|---|
Returns: | Word2VecModel instance |
New in version 1.2.0.
Sets initial learning rate (default: 0.025).
New in version 1.2.0.
Sets minCount, the minimum number of times a token must appear to be included in the word2vec model’s vocabulary (default: 5).
New in version 1.4.0.
Sets number of iterations (default: 1), which should be smaller than or equal to number of partitions.
New in version 1.2.0.
Bases: pyspark.mllib.feature.JavaVectorTransformer, pyspark.mllib.util.JavaSaveable, pyspark.mllib.util.JavaLoader
class for Word2Vec model
New in version 1.2.0.
Bases: object
Note
Experimental
Creates a ChiSquared feature selector.
Parameters: | numTopFeatures – number of features that selector will select. |
---|
>>> data = [
... LabeledPoint(0.0, SparseVector(3, {0: 8.0, 1: 7.0})),
... LabeledPoint(1.0, SparseVector(3, {1: 9.0, 2: 6.0})),
... LabeledPoint(1.0, [0.0, 9.0, 8.0]),
... LabeledPoint(2.0, [8.0, 9.0, 5.0])
... ]
>>> model = ChiSqSelector(1).fit(sc.parallelize(data))
>>> model.transform(SparseVector(3, {1: 9.0, 2: 6.0}))
SparseVector(1, {0: 6.0})
>>> model.transform(DenseVector([8.0, 9.0, 5.0]))
DenseVector([5.0])
New in version 1.4.0.
Returns a ChiSquared feature selector.
Parameters: | data – an RDD[LabeledPoint] containing the labeled dataset with categorical features. Real-valued features will be treated as categorical for each distinct value. Apply feature discretizer before using this function. |
---|
New in version 1.4.0.
Bases: pyspark.mllib.feature.JavaVectorTransformer
Note
Experimental
Represents a Chi Squared selector model.
New in version 1.4.0.
Bases: pyspark.mllib.feature.VectorTransformer
Note
Experimental
Scales each column of the vector, with the supplied weight vector. i.e the elementwise product.
>>> weight = Vectors.dense([1.0, 2.0, 3.0])
>>> eprod = ElementwiseProduct(weight)
>>> a = Vectors.dense([2.0, 1.0, 3.0])
>>> eprod.transform(a)
DenseVector([2.0, 2.0, 9.0])
>>> b = Vectors.dense([9.0, 3.0, 4.0])
>>> rdd = sc.parallelize([a, b])
>>> eprod.transform(rdd).collect()
[DenseVector([2.0, 2.0, 9.0]), DenseVector([9.0, 6.0, 12.0])]
New in version 1.5.0.
Note
Experimental
A Parallel FP-growth algorithm to mine frequent itemsets.
New in version 1.4.0.
Computes an FP-Growth model that contains frequent itemsets.
Parameters: |
|
---|
New in version 1.4.0.
Note
Experimental
A FP-Growth model for mining frequent itemsets using the Parallel FP-Growth algorithm.
>>> data = [["a", "b", "c"], ["a", "b", "d", "e"], ["a", "c", "e"], ["a", "c", "f"]]
>>> rdd = sc.parallelize(data, 2)
>>> model = FPGrowth.train(rdd, 0.6, 2)
>>> sorted(model.freqItemsets().collect())
[FreqItemset(items=[u'a'], freq=4), FreqItemset(items=[u'c'], freq=3), ...
New in version 1.4.0.
Note
Experimental
A parallel PrefixSpan algorithm to mine frequent sequential patterns. The PrefixSpan algorithm is described in J. Pei, et al., PrefixSpan: Mining Sequential Patterns Efficiently by Prefix-Projected Pattern Growth ([[http://doi.org/10.1109/ICDE.2001.914830]]).
New in version 1.6.0.
Finds the complete set of frequent sequential patterns in the input sequences of itemsets.
Parameters: |
|
---|
New in version 1.6.0.
Note
Experimental
Model fitted by PrefixSpan
>>> data = [
... [["a", "b"], ["c"]],
... [["a"], ["c", "b"], ["a", "b"]],
... [["a", "b"], ["e"]],
... [["f"]]]
>>> rdd = sc.parallelize(data, 2)
>>> model = PrefixSpan.train(rdd)
>>> sorted(model.freqSequences().collect())
[FreqSequence(sequence=[[u'a']], freq=3), FreqSequence(sequence=[[u'a'], [u'a']], freq=1), ...
New in version 1.6.0.
MLlib utilities for linear algebra. For dense vectors, MLlib uses the NumPy array type, so you can simply pass NumPy arrays around. For sparse vectors, users can construct a SparseVector object from MLlib or pass SciPy scipy.sparse column vectors if SciPy is available in their environment.
Bases: pyspark.mllib.linalg.Vector
A dense vector represented by a value array. We use numpy array for storage and arithmetics will be delegated to the underlying numpy array.
>>> v = Vectors.dense([1.0, 2.0])
>>> u = Vectors.dense([3.0, 4.0])
>>> v + u
DenseVector([4.0, 6.0])
>>> 2 - v
DenseVector([1.0, 0.0])
>>> v / 2
DenseVector([0.5, 1.0])
>>> v * u
DenseVector([3.0, 8.0])
>>> u / v
DenseVector([3.0, 2.0])
>>> u % 2
DenseVector([1.0, 0.0])
Compute the dot product of two Vectors. We support (Numpy array, list, SparseVector, or SciPy sparse) and a target NumPy array that is either 1- or 2-dimensional. Equivalent to calling numpy.dot of the two vectors.
>>> dense = DenseVector(array.array('d', [1., 2.]))
>>> dense.dot(dense)
5.0
>>> dense.dot(SparseVector(2, [0, 1], [2., 1.]))
4.0
>>> dense.dot(range(1, 3))
5.0
>>> dense.dot(np.array(range(1, 3)))
5.0
>>> dense.dot([1.,])
Traceback (most recent call last):
...
AssertionError: dimension mismatch
>>> dense.dot(np.reshape([1., 2., 3., 4.], (2, 2), order='F'))
array([ 5., 11.])
>>> dense.dot(np.reshape([1., 2., 3.], (3, 1), order='F'))
Traceback (most recent call last):
...
AssertionError: dimension mismatch
Calculates the norm of a DenseVector.
>>> a = DenseVector([0, -1, 2, -3])
>>> a.norm(2)
3.7...
>>> a.norm(1)
6.0
Parse string representation back into the DenseVector.
>>> DenseVector.parse(' [ 0.0,1.0,2.0, 3.0]')
DenseVector([0.0, 1.0, 2.0, 3.0])
Squared distance of two Vectors.
>>> dense1 = DenseVector(array.array('d', [1., 2.]))
>>> dense1.squared_distance(dense1)
0.0
>>> dense2 = np.array([2., 1.])
>>> dense1.squared_distance(dense2)
2.0
>>> dense3 = [2., 1.]
>>> dense1.squared_distance(dense3)
2.0
>>> sparse1 = SparseVector(2, [0, 1], [2., 1.])
>>> dense1.squared_distance(sparse1)
2.0
>>> dense1.squared_distance([1.,])
Traceback (most recent call last):
...
AssertionError: dimension mismatch
>>> dense1.squared_distance(SparseVector(1, [0,], [1.,]))
Traceback (most recent call last):
...
AssertionError: dimension mismatch
Bases: pyspark.mllib.linalg.Vector
A simple sparse vector class for passing data to MLlib. Users may alternatively pass SciPy’s {scipy.sparse} data types.
Dot product with a SparseVector or 1- or 2-dimensional Numpy array.
>>> a = SparseVector(4, [1, 3], [3.0, 4.0])
>>> a.dot(a)
25.0
>>> a.dot(array.array('d', [1., 2., 3., 4.]))
22.0
>>> b = SparseVector(4, [2], [1.0])
>>> a.dot(b)
0.0
>>> a.dot(np.array([[1, 1], [2, 2], [3, 3], [4, 4]]))
array([ 22., 22.])
>>> a.dot([1., 2., 3.])
Traceback (most recent call last):
...
AssertionError: dimension mismatch
>>> a.dot(np.array([1., 2.]))
Traceback (most recent call last):
...
AssertionError: dimension mismatch
>>> a.dot(DenseVector([1., 2.]))
Traceback (most recent call last):
...
AssertionError: dimension mismatch
>>> a.dot(np.zeros((3, 2)))
Traceback (most recent call last):
...
AssertionError: dimension mismatch
A list of indices corresponding to active entries.
Calculates the norm of a SparseVector.
>>> a = SparseVector(4, [0, 1], [3., -4.])
>>> a.norm(1)
7.0
>>> a.norm(2)
5.0
Number of nonzero elements. This scans all active values and count non zeros.
Parse string representation back into the SparseVector.
>>> SparseVector.parse(' (4, [0,1 ],[ 4.0,5.0] )')
SparseVector(4, {0: 4.0, 1: 5.0})
Size of the vector.
Squared distance from a SparseVector or 1-dimensional NumPy array.
>>> a = SparseVector(4, [1, 3], [3.0, 4.0])
>>> a.squared_distance(a)
0.0
>>> a.squared_distance(array.array('d', [1., 2., 3., 4.]))
11.0
>>> a.squared_distance(np.array([1., 2., 3., 4.]))
11.0
>>> b = SparseVector(4, [2], [1.0])
>>> a.squared_distance(b)
26.0
>>> b.squared_distance(a)
26.0
>>> b.squared_distance([1., 2.])
Traceback (most recent call last):
...
AssertionError: dimension mismatch
>>> b.squared_distance(SparseVector(3, [1,], [1.0,]))
Traceback (most recent call last):
...
AssertionError: dimension mismatch
A list of values corresponding to active entries.
Bases: object
Factory methods for working with vectors. Note that dense vectors are simply represented as NumPy array objects, so there is no need to covert them for use in MLlib. For sparse vectors, the factory methods in this class create an MLlib-compatible type, or users can pass in SciPy’s scipy.sparse column vectors.
Create a dense vector of 64-bit floats from a Python list or numbers.
>>> Vectors.dense([1, 2, 3])
DenseVector([1.0, 2.0, 3.0])
>>> Vectors.dense(1.0, 2.0)
DenseVector([1.0, 2.0])
Parse a string representation back into the Vector.
>>> Vectors.parse('[2,1,2 ]')
DenseVector([2.0, 1.0, 2.0])
>>> Vectors.parse(' ( 100, [0], [2])')
SparseVector(100, {0: 2.0})
Create a sparse vector, using either a dictionary, a list of (index, value) pairs, or two separate arrays of indices and values (sorted by index).
Parameters: |
|
---|
>>> Vectors.sparse(4, {1: 1.0, 3: 5.5})
SparseVector(4, {1: 1.0, 3: 5.5})
>>> Vectors.sparse(4, [(1, 1.0), (3, 5.5)])
SparseVector(4, {1: 1.0, 3: 5.5})
>>> Vectors.sparse(4, [1, 3], [1.0, 5.5])
SparseVector(4, {1: 1.0, 3: 5.5})
Squared distance between two vectors. a and b can be of type SparseVector, DenseVector, np.ndarray or array.array.
>>> a = Vectors.sparse(4, [(0, 1), (3, 4)])
>>> b = Vectors.dense([2, 5, 4, 1])
>>> a.squared_distance(b)
51.0
Bases: pyspark.mllib.linalg.Matrix
Column-major dense matrix.
Bases: pyspark.mllib.linalg.Matrix
Sparse Matrix stored in CSC format.
Package for distributed linear algebra.
Bases: object
Note
Experimental
Represents a distributively stored matrix backed by one or more RDDs.
Bases: pyspark.mllib.linalg.distributed.DistributedMatrix
Note
Experimental
Represents a row-oriented distributed Matrix with no meaningful row indices.
Parameters: |
|
---|
Get or compute the number of cols.
>>> rows = sc.parallelize([[1, 2, 3], [4, 5, 6],
... [7, 8, 9], [10, 11, 12]])
>>> mat = RowMatrix(rows)
>>> print(mat.numCols())
3
>>> mat = RowMatrix(rows, 7, 6)
>>> print(mat.numCols())
6
Bases: object
Note
Experimental
Represents a row of an IndexedRowMatrix.
Just a wrapper over a (long, vector) tuple.
Parameters: |
|
---|
Bases: pyspark.mllib.linalg.distributed.DistributedMatrix
Note
Experimental
Represents a row-oriented distributed Matrix with indexed rows.
Parameters: |
|
---|
Get or compute the number of cols.
>>> rows = sc.parallelize([IndexedRow(0, [1, 2, 3]),
... IndexedRow(1, [4, 5, 6]),
... IndexedRow(2, [7, 8, 9]),
... IndexedRow(3, [10, 11, 12])])
>>> mat = IndexedRowMatrix(rows)
>>> print(mat.numCols())
3
>>> mat = IndexedRowMatrix(rows, 7, 6)
>>> print(mat.numCols())
6
Get or compute the number of rows.
>>> rows = sc.parallelize([IndexedRow(0, [1, 2, 3]),
... IndexedRow(1, [4, 5, 6]),
... IndexedRow(2, [7, 8, 9]),
... IndexedRow(3, [10, 11, 12])])
>>> mat = IndexedRowMatrix(rows)
>>> print(mat.numRows())
4
>>> mat = IndexedRowMatrix(rows, 7, 6)
>>> print(mat.numRows())
7
Rows of the IndexedRowMatrix stored as an RDD of IndexedRows.
>>> mat = IndexedRowMatrix(sc.parallelize([IndexedRow(0, [1, 2, 3]),
... IndexedRow(1, [4, 5, 6])]))
>>> rows = mat.rows
>>> rows.first()
IndexedRow(0, [1.0,2.0,3.0])
Convert this matrix to a BlockMatrix.
Parameters: |
|
---|
>>> rows = sc.parallelize([IndexedRow(0, [1, 2, 3]),
... IndexedRow(6, [4, 5, 6])])
>>> mat = IndexedRowMatrix(rows).toBlockMatrix()
>>> # This IndexedRowMatrix will have 7 effective rows, due to
>>> # the highest row index being 6, and the ensuing
>>> # BlockMatrix will have 7 rows as well.
>>> print(mat.numRows())
7
>>> print(mat.numCols())
3
Convert this matrix to a CoordinateMatrix.
>>> rows = sc.parallelize([IndexedRow(0, [1, 0]),
... IndexedRow(6, [0, 5])])
>>> mat = IndexedRowMatrix(rows).toCoordinateMatrix()
>>> mat.entries.take(3)
[MatrixEntry(0, 0, 1.0), MatrixEntry(0, 1, 0.0), MatrixEntry(6, 0, 0.0)]
Bases: object
Note
Experimental
Represents an entry of a CoordinateMatrix.
Just a wrapper over a (long, long, float) tuple.
Parameters: |
|
---|
Bases: pyspark.mllib.linalg.distributed.DistributedMatrix
Note
Experimental
Represents a matrix in coordinate format.
Parameters: |
|
---|
Entries of the CoordinateMatrix stored as an RDD of MatrixEntries.
>>> mat = CoordinateMatrix(sc.parallelize([MatrixEntry(0, 0, 1.2),
... MatrixEntry(6, 4, 2.1)]))
>>> entries = mat.entries
>>> entries.first()
MatrixEntry(0, 0, 1.2)
Get or compute the number of cols.
>>> entries = sc.parallelize([MatrixEntry(0, 0, 1.2),
... MatrixEntry(1, 0, 2),
... MatrixEntry(2, 1, 3.7)])
>>> mat = CoordinateMatrix(entries)
>>> print(mat.numCols())
2
>>> mat = CoordinateMatrix(entries, 7, 6)
>>> print(mat.numCols())
6
Get or compute the number of rows.
>>> entries = sc.parallelize([MatrixEntry(0, 0, 1.2),
... MatrixEntry(1, 0, 2),
... MatrixEntry(2, 1, 3.7)])
>>> mat = CoordinateMatrix(entries)
>>> print(mat.numRows())
3
>>> mat = CoordinateMatrix(entries, 7, 6)
>>> print(mat.numRows())
7
Convert this matrix to a BlockMatrix.
Parameters: |
|
---|
>>> entries = sc.parallelize([MatrixEntry(0, 0, 1.2),
... MatrixEntry(6, 4, 2.1)])
>>> mat = CoordinateMatrix(entries).toBlockMatrix()
>>> # This CoordinateMatrix will have 7 effective rows, due to
>>> # the highest row index being 6, and the ensuing
>>> # BlockMatrix will have 7 rows as well.
>>> print(mat.numRows())
7
>>> # This CoordinateMatrix will have 5 columns, due to the
>>> # highest column index being 4, and the ensuing
>>> # BlockMatrix will have 5 columns as well.
>>> print(mat.numCols())
5
Convert this matrix to an IndexedRowMatrix.
>>> entries = sc.parallelize([MatrixEntry(0, 0, 1.2),
... MatrixEntry(6, 4, 2.1)])
>>> mat = CoordinateMatrix(entries).toIndexedRowMatrix()
>>> # This CoordinateMatrix will have 7 effective rows, due to
>>> # the highest row index being 6, and the ensuing
>>> # IndexedRowMatrix will have 7 rows as well.
>>> print(mat.numRows())
7
>>> # This CoordinateMatrix will have 5 columns, due to the
>>> # highest column index being 4, and the ensuing
>>> # IndexedRowMatrix will have 5 columns as well.
>>> print(mat.numCols())
5
Convert this matrix to a RowMatrix.
>>> entries = sc.parallelize([MatrixEntry(0, 0, 1.2),
... MatrixEntry(6, 4, 2.1)])
>>> mat = CoordinateMatrix(entries).toRowMatrix()
>>> # This CoordinateMatrix will have 7 effective rows, due to
>>> # the highest row index being 6, but the ensuing RowMatrix
>>> # will only have 2 rows since there are only entries on 2
>>> # unique rows.
>>> print(mat.numRows())
2
>>> # This CoordinateMatrix will have 5 columns, due to the
>>> # highest column index being 4, and the ensuing RowMatrix
>>> # will have 5 columns as well.
>>> print(mat.numCols())
5
Bases: pyspark.mllib.linalg.distributed.DistributedMatrix
Note
Experimental
Represents a distributed matrix in blocks of local matrices.
Parameters: |
|
---|
Adds two block matrices together. The matrices must have the same size and matching rowsPerBlock and colsPerBlock values. If one of the sub matrix blocks that are being added is a SparseMatrix, the resulting sub matrix block will also be a SparseMatrix, even if it is being added to a DenseMatrix. If two dense sub matrix blocks are added, the output block will also be a DenseMatrix.
>>> dm1 = Matrices.dense(3, 2, [1, 2, 3, 4, 5, 6])
>>> dm2 = Matrices.dense(3, 2, [7, 8, 9, 10, 11, 12])
>>> sm = Matrices.sparse(3, 2, [0, 1, 3], [0, 1, 2], [7, 11, 12])
>>> blocks1 = sc.parallelize([((0, 0), dm1), ((1, 0), dm2)])
>>> blocks2 = sc.parallelize([((0, 0), dm1), ((1, 0), dm2)])
>>> blocks3 = sc.parallelize([((0, 0), sm), ((1, 0), dm2)])
>>> mat1 = BlockMatrix(blocks1, 3, 2)
>>> mat2 = BlockMatrix(blocks2, 3, 2)
>>> mat3 = BlockMatrix(blocks3, 3, 2)
>>> mat1.add(mat2).toLocalMatrix()
DenseMatrix(6, 2, [2.0, 4.0, 6.0, 14.0, 16.0, 18.0, 8.0, 10.0, 12.0, 20.0, 22.0, 24.0], 0)
>>> mat1.add(mat3).toLocalMatrix()
DenseMatrix(6, 2, [8.0, 2.0, 3.0, 14.0, 16.0, 18.0, 4.0, 16.0, 18.0, 20.0, 22.0, 24.0], 0)
The RDD of sub-matrix blocks ((blockRowIndex, blockColIndex), sub-matrix) that form this distributed matrix.
>>> mat = BlockMatrix(
... sc.parallelize([((0, 0), Matrices.dense(3, 2, [1, 2, 3, 4, 5, 6])),
... ((1, 0), Matrices.dense(3, 2, [7, 8, 9, 10, 11, 12]))]), 3, 2)
>>> blocks = mat.blocks
>>> blocks.first()
((0, 0), DenseMatrix(3, 2, [1.0, 2.0, 3.0, 4.0, 5.0, 6.0], 0))
Number of columns that make up each block.
>>> blocks = sc.parallelize([((0, 0), Matrices.dense(3, 2, [1, 2, 3, 4, 5, 6])),
... ((1, 0), Matrices.dense(3, 2, [7, 8, 9, 10, 11, 12]))])
>>> mat = BlockMatrix(blocks, 3, 2)
>>> mat.colsPerBlock
2
Left multiplies this BlockMatrix by other, another BlockMatrix. The colsPerBlock of this matrix must equal the rowsPerBlock of other. If other contains any SparseMatrix blocks, they will have to be converted to DenseMatrix blocks. The output BlockMatrix will only consist of DenseMatrix blocks. This may cause some performance issues until support for multiplying two sparse matrices is added.
>>> dm1 = Matrices.dense(2, 3, [1, 2, 3, 4, 5, 6])
>>> dm2 = Matrices.dense(2, 3, [7, 8, 9, 10, 11, 12])
>>> dm3 = Matrices.dense(3, 2, [1, 2, 3, 4, 5, 6])
>>> dm4 = Matrices.dense(3, 2, [7, 8, 9, 10, 11, 12])
>>> sm = Matrices.sparse(3, 2, [0, 1, 3], [0, 1, 2], [7, 11, 12])
>>> blocks1 = sc.parallelize([((0, 0), dm1), ((0, 1), dm2)])
>>> blocks2 = sc.parallelize([((0, 0), dm3), ((1, 0), dm4)])
>>> blocks3 = sc.parallelize([((0, 0), sm), ((1, 0), dm4)])
>>> mat1 = BlockMatrix(blocks1, 2, 3)
>>> mat2 = BlockMatrix(blocks2, 3, 2)
>>> mat3 = BlockMatrix(blocks3, 3, 2)
>>> mat1.multiply(mat2).toLocalMatrix()
DenseMatrix(2, 2, [242.0, 272.0, 350.0, 398.0], 0)
>>> mat1.multiply(mat3).toLocalMatrix()
DenseMatrix(2, 2, [227.0, 258.0, 394.0, 450.0], 0)
Number of columns of blocks in the BlockMatrix.
>>> blocks = sc.parallelize([((0, 0), Matrices.dense(3, 2, [1, 2, 3, 4, 5, 6])),
... ((1, 0), Matrices.dense(3, 2, [7, 8, 9, 10, 11, 12]))])
>>> mat = BlockMatrix(blocks, 3, 2)
>>> mat.numColBlocks
1
Get or compute the number of cols.
>>> blocks = sc.parallelize([((0, 0), Matrices.dense(3, 2, [1, 2, 3, 4, 5, 6])),
... ((1, 0), Matrices.dense(3, 2, [7, 8, 9, 10, 11, 12]))])
>>> mat = BlockMatrix(blocks, 3, 2)
>>> print(mat.numCols())
2
>>> mat = BlockMatrix(blocks, 3, 2, 7, 6)
>>> print(mat.numCols())
6
Number of rows of blocks in the BlockMatrix.
>>> blocks = sc.parallelize([((0, 0), Matrices.dense(3, 2, [1, 2, 3, 4, 5, 6])),
... ((1, 0), Matrices.dense(3, 2, [7, 8, 9, 10, 11, 12]))])
>>> mat = BlockMatrix(blocks, 3, 2)
>>> mat.numRowBlocks
2
Get or compute the number of rows.
>>> blocks = sc.parallelize([((0, 0), Matrices.dense(3, 2, [1, 2, 3, 4, 5, 6])),
... ((1, 0), Matrices.dense(3, 2, [7, 8, 9, 10, 11, 12]))])
>>> mat = BlockMatrix(blocks, 3, 2)
>>> print(mat.numRows())
6
>>> mat = BlockMatrix(blocks, 3, 2, 7, 6)
>>> print(mat.numRows())
7
Number of rows that make up each block.
>>> blocks = sc.parallelize([((0, 0), Matrices.dense(3, 2, [1, 2, 3, 4, 5, 6])),
... ((1, 0), Matrices.dense(3, 2, [7, 8, 9, 10, 11, 12]))])
>>> mat = BlockMatrix(blocks, 3, 2)
>>> mat.rowsPerBlock
3
Convert this matrix to a CoordinateMatrix.
>>> blocks = sc.parallelize([((0, 0), Matrices.dense(1, 2, [1, 2])),
... ((1, 0), Matrices.dense(1, 2, [7, 8]))])
>>> mat = BlockMatrix(blocks, 1, 2).toCoordinateMatrix()
>>> mat.entries.take(3)
[MatrixEntry(0, 0, 1.0), MatrixEntry(0, 1, 2.0), MatrixEntry(1, 0, 7.0)]
Convert this matrix to an IndexedRowMatrix.
>>> blocks = sc.parallelize([((0, 0), Matrices.dense(3, 2, [1, 2, 3, 4, 5, 6])),
... ((1, 0), Matrices.dense(3, 2, [7, 8, 9, 10, 11, 12]))])
>>> mat = BlockMatrix(blocks, 3, 2).toIndexedRowMatrix()
>>> # This BlockMatrix will have 6 effective rows, due to
>>> # having two sub-matrix blocks stacked, each with 3 rows.
>>> # The ensuing IndexedRowMatrix will also have 6 rows.
>>> print(mat.numRows())
6
>>> # This BlockMatrix will have 2 effective columns, due to
>>> # having two sub-matrix blocks stacked, each with 2 columns.
>>> # The ensuing IndexedRowMatrix will also have 2 columns.
>>> print(mat.numCols())
2
Collect the distributed matrix on the driver as a DenseMatrix.
>>> blocks = sc.parallelize([((0, 0), Matrices.dense(3, 2, [1, 2, 3, 4, 5, 6])),
... ((1, 0), Matrices.dense(3, 2, [7, 8, 9, 10, 11, 12]))])
>>> mat = BlockMatrix(blocks, 3, 2).toLocalMatrix()
>>> # This BlockMatrix will have 6 effective rows, due to
>>> # having two sub-matrix blocks stacked, each with 3 rows.
>>> # The ensuing DenseMatrix will also have 6 rows.
>>> print(mat.numRows)
6
>>> # This BlockMatrix will have 2 effective columns, due to
>>> # having two sub-matrix blocks stacked, each with 2
>>> # columns. The ensuing DenseMatrix will also have 2 columns.
>>> print(mat.numCols)
2
Python package for random data generation.
Generator methods for creating RDDs comprised of i.i.d samples from some distribution.
New in version 1.1.0.
Generates an RDD comprised of i.i.d. samples from the Exponential distribution with the input mean.
Parameters: |
|
---|---|
Returns: | RDD of float comprised of i.i.d. samples ~ Exp(mean). |
>>> mean = 2.0
>>> x = RandomRDDs.exponentialRDD(sc, mean, 1000, seed=2)
>>> stats = x.stats()
>>> stats.count()
1000
>>> abs(stats.mean() - mean) < 0.5
True
>>> from math import sqrt
>>> abs(stats.stdev() - sqrt(mean)) < 0.5
True
New in version 1.3.0.
Generates an RDD comprised of vectors containing i.i.d. samples drawn from the Exponential distribution with the input mean.
Parameters: |
|
---|---|
Returns: | RDD of Vector with vectors containing i.i.d. samples ~ Exp(mean). |
>>> import numpy as np
>>> mean = 0.5
>>> rdd = RandomRDDs.exponentialVectorRDD(sc, mean, 100, 100, seed=1)
>>> mat = np.mat(rdd.collect())
>>> mat.shape
(100, 100)
>>> abs(mat.mean() - mean) < 0.5
True
>>> from math import sqrt
>>> abs(mat.std() - sqrt(mean)) < 0.5
True
New in version 1.3.0.
Generates an RDD comprised of i.i.d. samples from the Gamma distribution with the input shape and scale.
Parameters: |
|
---|---|
Returns: | RDD of float comprised of i.i.d. samples ~ Gamma(shape, scale). |
>>> from math import sqrt
>>> shape = 1.0
>>> scale = 2.0
>>> expMean = shape * scale
>>> expStd = sqrt(shape * scale * scale)
>>> x = RandomRDDs.gammaRDD(sc, shape, scale, 1000, seed=2)
>>> stats = x.stats()
>>> stats.count()
1000
>>> abs(stats.mean() - expMean) < 0.5
True
>>> abs(stats.stdev() - expStd) < 0.5
True
New in version 1.3.0.
Generates an RDD comprised of vectors containing i.i.d. samples drawn from the Gamma distribution.
Parameters: |
|
---|---|
Returns: | RDD of Vector with vectors containing i.i.d. samples ~ Gamma(shape, scale). |
>>> import numpy as np
>>> from math import sqrt
>>> shape = 1.0
>>> scale = 2.0
>>> expMean = shape * scale
>>> expStd = sqrt(shape * scale * scale)
>>> mat = np.matrix(RandomRDDs.gammaVectorRDD(sc, shape, scale, 100, 100, seed=1).collect())
>>> mat.shape
(100, 100)
>>> abs(mat.mean() - expMean) < 0.1
True
>>> abs(mat.std() - expStd) < 0.1
True
New in version 1.3.0.
Generates an RDD comprised of i.i.d. samples from the log normal distribution with the input mean and standard distribution.
Parameters: |
|
---|---|
Returns: | RDD of float comprised of i.i.d. samples ~ log N(mean, std). |
>>> from math import sqrt, exp
>>> mean = 0.0
>>> std = 1.0
>>> expMean = exp(mean + 0.5 * std * std)
>>> expStd = sqrt((exp(std * std) - 1.0) * exp(2.0 * mean + std * std))
>>> x = RandomRDDs.logNormalRDD(sc, mean, std, 1000, seed=2)
>>> stats = x.stats()
>>> stats.count()
1000
>>> abs(stats.mean() - expMean) < 0.5
True
>>> from math import sqrt
>>> abs(stats.stdev() - expStd) < 0.5
True
New in version 1.3.0.
Generates an RDD comprised of vectors containing i.i.d. samples drawn from the log normal distribution.
Parameters: |
|
---|---|
Returns: | RDD of Vector with vectors containing i.i.d. samples ~ log N(mean, std). |
>>> import numpy as np
>>> from math import sqrt, exp
>>> mean = 0.0
>>> std = 1.0
>>> expMean = exp(mean + 0.5 * std * std)
>>> expStd = sqrt((exp(std * std) - 1.0) * exp(2.0 * mean + std * std))
>>> m = RandomRDDs.logNormalVectorRDD(sc, mean, std, 100, 100, seed=1).collect()
>>> mat = np.matrix(m)
>>> mat.shape
(100, 100)
>>> abs(mat.mean() - expMean) < 0.1
True
>>> abs(mat.std() - expStd) < 0.1
True
New in version 1.3.0.
Generates an RDD comprised of i.i.d. samples from the standard normal distribution.
To transform the distribution in the generated RDD from standard normal to some other normal N(mean, sigma^2), use RandomRDDs.normal(sc, n, p, seed) .map(lambda v: mean + sigma * v)
Parameters: |
|
---|---|
Returns: | RDD of float comprised of i.i.d. samples ~ N(0.0, 1.0). |
>>> x = RandomRDDs.normalRDD(sc, 1000, seed=1)
>>> stats = x.stats()
>>> stats.count()
1000
>>> abs(stats.mean() - 0.0) < 0.1
True
>>> abs(stats.stdev() - 1.0) < 0.1
True
New in version 1.1.0.
Generates an RDD comprised of vectors containing i.i.d. samples drawn from the standard normal distribution.
Parameters: |
|
---|---|
Returns: | RDD of Vector with vectors containing i.i.d. samples ~ N(0.0, 1.0). |
>>> import numpy as np
>>> mat = np.matrix(RandomRDDs.normalVectorRDD(sc, 100, 100, seed=1).collect())
>>> mat.shape
(100, 100)
>>> abs(mat.mean() - 0.0) < 0.1
True
>>> abs(mat.std() - 1.0) < 0.1
True
New in version 1.1.0.
Generates an RDD comprised of i.i.d. samples from the Poisson distribution with the input mean.
Parameters: |
|
---|---|
Returns: | RDD of float comprised of i.i.d. samples ~ Pois(mean). |
>>> mean = 100.0
>>> x = RandomRDDs.poissonRDD(sc, mean, 1000, seed=2)
>>> stats = x.stats()
>>> stats.count()
1000
>>> abs(stats.mean() - mean) < 0.5
True
>>> from math import sqrt
>>> abs(stats.stdev() - sqrt(mean)) < 0.5
True
New in version 1.1.0.
Generates an RDD comprised of vectors containing i.i.d. samples drawn from the Poisson distribution with the input mean.
Parameters: |
|
---|---|
Returns: | RDD of Vector with vectors containing i.i.d. samples ~ Pois(mean). |
>>> import numpy as np
>>> mean = 100.0
>>> rdd = RandomRDDs.poissonVectorRDD(sc, mean, 100, 100, seed=1)
>>> mat = np.mat(rdd.collect())
>>> mat.shape
(100, 100)
>>> abs(mat.mean() - mean) < 0.5
True
>>> from math import sqrt
>>> abs(mat.std() - sqrt(mean)) < 0.5
True
New in version 1.1.0.
Generates an RDD comprised of i.i.d. samples from the uniform distribution U(0.0, 1.0).
To transform the distribution in the generated RDD from U(0.0, 1.0) to U(a, b), use RandomRDDs.uniformRDD(sc, n, p, seed) .map(lambda v: a + (b - a) * v)
Parameters: |
|
---|---|
Returns: | RDD of float comprised of i.i.d. samples ~ U(0.0, 1.0). |
>>> x = RandomRDDs.uniformRDD(sc, 100).collect()
>>> len(x)
100
>>> max(x) <= 1.0 and min(x) >= 0.0
True
>>> RandomRDDs.uniformRDD(sc, 100, 4).getNumPartitions()
4
>>> parts = RandomRDDs.uniformRDD(sc, 100, seed=4).getNumPartitions()
>>> parts == sc.defaultParallelism
True
New in version 1.1.0.
Generates an RDD comprised of vectors containing i.i.d. samples drawn from the uniform distribution U(0.0, 1.0).
Parameters: |
|
---|---|
Returns: | RDD of Vector with vectors containing i.i.d samples ~ U(0.0, 1.0). |
>>> import numpy as np
>>> mat = np.matrix(RandomRDDs.uniformVectorRDD(sc, 10, 10).collect())
>>> mat.shape
(10, 10)
>>> mat.max() <= 1.0 and mat.min() >= 0.0
True
>>> RandomRDDs.uniformVectorRDD(sc, 10, 10, 4).getNumPartitions()
4
New in version 1.1.0.
A matrix factorisation model trained by regularized alternating least-squares.
>>> r1 = (1, 1, 1.0)
>>> r2 = (1, 2, 2.0)
>>> r3 = (2, 1, 2.0)
>>> ratings = sc.parallelize([r1, r2, r3])
>>> model = ALS.trainImplicit(ratings, 1, seed=10)
>>> model.predict(2, 2)
0.4...
>>> testset = sc.parallelize([(1, 2), (1, 1)])
>>> model = ALS.train(ratings, 2, seed=0)
>>> model.predictAll(testset).collect()
[Rating(user=1, product=1, rating=1.0...), Rating(user=1, product=2, rating=1.9...)]
>>> model = ALS.train(ratings, 4, seed=10)
>>> model.userFeatures().collect()
[(1, array('d', [...])), (2, array('d', [...]))]
>>> model.recommendUsers(1, 2)
[Rating(user=2, product=1, rating=1.9...), Rating(user=1, product=1, rating=1.0...)]
>>> model.recommendProducts(1, 2)
[Rating(user=1, product=2, rating=1.9...), Rating(user=1, product=1, rating=1.0...)]
>>> model.rank
4
>>> first_user = model.userFeatures().take(1)[0]
>>> latents = first_user[1]
>>> len(latents)
4
>>> model.productFeatures().collect()
[(1, array('d', [...])), (2, array('d', [...]))]
>>> first_product = model.productFeatures().take(1)[0]
>>> latents = first_product[1]
>>> len(latents)
4
>>> products_for_users = model.recommendProductsForUsers(1).collect()
>>> len(products_for_users)
2
>>> products_for_users[0]
(1, (Rating(user=1, product=2, rating=...),))
>>> users_for_products = model.recommendUsersForProducts(1).collect()
>>> len(users_for_products)
2
>>> users_for_products[0]
(1, (Rating(user=2, product=1, rating=...),))
>>> model = ALS.train(ratings, 1, nonnegative=True, seed=10)
>>> model.predict(2, 2)
3.73...
>>> df = sqlContext.createDataFrame([Rating(1, 1, 1.0), Rating(1, 2, 2.0), Rating(2, 1, 2.0)])
>>> model = ALS.train(df, 1, nonnegative=True, seed=10)
>>> model.predict(2, 2)
3.73...
>>> model = ALS.trainImplicit(ratings, 1, nonnegative=True, seed=10)
>>> model.predict(2, 2)
0.4...
>>> import os, tempfile
>>> path = tempfile.mkdtemp()
>>> model.save(sc, path)
>>> sameModel = MatrixFactorizationModel.load(sc, path)
>>> sameModel.predict(2, 2)
0.4...
>>> sameModel.predictAll(testset).collect()
[Rating(...
>>> from shutil import rmtree
>>> try:
... rmtree(path)
... except OSError:
... pass
New in version 0.9.0.
Predicts rating for the given user and product.
New in version 0.9.0.
Returns a list of predicted ratings for input user and product pairs.
New in version 0.9.0.
Returns a paired RDD, where the first element is the product and the second is an array of features corresponding to that product.
New in version 1.2.0.
Recommends the top “num” number of products for a given user and returns a list of Rating objects sorted by the predicted rating in descending order.
New in version 1.4.0.
Recommends top “num” products for all users. The number returned may be less than this.
Recommends the top “num” number of users for a given product and returns a list of Rating objects sorted by the predicted rating in descending order.
New in version 1.4.0.
Alternating Least Squares matrix factorization
New in version 0.9.0.
Train a matrix factorization model given an RDD of ratings given by users to some products, in the form of (userID, productID, rating) pairs. We approximate the ratings matrix as the product of two lower-rank matrices of a given rank (number of features). To solve for these features, we run a given number of iterations of ALS. This is done using a level of parallelism given by blocks.
New in version 0.9.0.
Train a matrix factorization model given an RDD of ‘implicit preferences’ given by users to some products, in the form of (userID, productID, preference) pairs. We approximate the ratings matrix as the product of two lower-rank matrices of a given rank (number of features). To solve for these features, we run a given number of iterations of ALS. This is done using a level of parallelism given by blocks.
New in version 0.9.0.
Class that represents the features and labels of a data point.
Parameters: |
|
---|
Note: ‘label’ and ‘features’ are accessible as class attributes.
New in version 1.0.0.
A linear model that has a vector of coefficients and an intercept.
Parameters: |
|
---|
New in version 0.9.0.
A linear regression model derived from a least-squares fit.
>>> from pyspark.mllib.regression import LabeledPoint
>>> data = [
... LabeledPoint(0.0, [0.0]),
... LabeledPoint(1.0, [1.0]),
... LabeledPoint(3.0, [2.0]),
... LabeledPoint(2.0, [3.0])
... ]
>>> lrm = LinearRegressionWithSGD.train(sc.parallelize(data), iterations=10,
... initialWeights=np.array([1.0]))
>>> abs(lrm.predict(np.array([0.0])) - 0) < 0.5
True
>>> abs(lrm.predict(np.array([1.0])) - 1) < 0.5
True
>>> abs(lrm.predict(SparseVector(1, {0: 1.0})) - 1) < 0.5
True
>>> abs(lrm.predict(sc.parallelize([[1.0]])).collect()[0] - 1) < 0.5
True
>>> import os, tempfile
>>> path = tempfile.mkdtemp()
>>> lrm.save(sc, path)
>>> sameModel = LinearRegressionModel.load(sc, path)
>>> abs(sameModel.predict(np.array([0.0])) - 0) < 0.5
True
>>> abs(sameModel.predict(np.array([1.0])) - 1) < 0.5
True
>>> abs(sameModel.predict(SparseVector(1, {0: 1.0})) - 1) < 0.5
True
>>> from shutil import rmtree
>>> try:
... rmtree(path)
... except:
... pass
>>> data = [
... LabeledPoint(0.0, SparseVector(1, {0: 0.0})),
... LabeledPoint(1.0, SparseVector(1, {0: 1.0})),
... LabeledPoint(3.0, SparseVector(1, {0: 2.0})),
... LabeledPoint(2.0, SparseVector(1, {0: 3.0}))
... ]
>>> lrm = LinearRegressionWithSGD.train(sc.parallelize(data), iterations=10,
... initialWeights=array([1.0]))
>>> abs(lrm.predict(array([0.0])) - 0) < 0.5
True
>>> abs(lrm.predict(SparseVector(1, {0: 1.0})) - 1) < 0.5
True
>>> lrm = LinearRegressionWithSGD.train(sc.parallelize(data), iterations=10, step=1.0,
... miniBatchFraction=1.0, initialWeights=array([1.0]), regParam=0.1, regType="l2",
... intercept=True, validateData=True)
>>> abs(lrm.predict(array([0.0])) - 0) < 0.5
True
>>> abs(lrm.predict(SparseVector(1, {0: 1.0})) - 1) < 0.5
True
New in version 0.9.0.
Intercept computed for this model.
New in version 1.0.0.
Predict the value of the dependent variable given a vector or an RDD of vectors containing values for the independent variables.
New in version 0.9.0.
Weights computed for every feature.
New in version 1.0.0.
Train a linear regression model with no regularization using Stochastic Gradient Descent. This solves the least squares regression formulation
f(weights) = 1/n ||A weights-y||^2^
(which is the mean squared error). Here the data matrix has n rows, and the input RDD holds the set of rows of A, each with its corresponding right hand side label y. See also the documentation for the precise formulation.
New in version 0.9.0.
Train a linear regression model using Stochastic Gradient Descent (SGD). This solves the least squares regression formulation
f(weights) = 1/(2n) ||A weights - y||^2,
which is the mean squared error. Here the data matrix has n rows, and the input RDD holds the set of rows of A, each with its corresponding right hand side label y. See also the documentation for the precise formulation.
Parameters: |
|
---|
New in version 0.9.0.
A linear regression model derived from a least-squares fit with an l_2 penalty term.
>>> from pyspark.mllib.regression import LabeledPoint
>>> data = [
... LabeledPoint(0.0, [0.0]),
... LabeledPoint(1.0, [1.0]),
... LabeledPoint(3.0, [2.0]),
... LabeledPoint(2.0, [3.0])
... ]
>>> lrm = RidgeRegressionWithSGD.train(sc.parallelize(data), iterations=10,
... initialWeights=array([1.0]))
>>> abs(lrm.predict(np.array([0.0])) - 0) < 0.5
True
>>> abs(lrm.predict(np.array([1.0])) - 1) < 0.5
True
>>> abs(lrm.predict(SparseVector(1, {0: 1.0})) - 1) < 0.5
True
>>> abs(lrm.predict(sc.parallelize([[1.0]])).collect()[0] - 1) < 0.5
True
>>> import os, tempfile
>>> path = tempfile.mkdtemp()
>>> lrm.save(sc, path)
>>> sameModel = RidgeRegressionModel.load(sc, path)
>>> abs(sameModel.predict(np.array([0.0])) - 0) < 0.5
True
>>> abs(sameModel.predict(np.array([1.0])) - 1) < 0.5
True
>>> abs(sameModel.predict(SparseVector(1, {0: 1.0})) - 1) < 0.5
True
>>> from shutil import rmtree
>>> try:
... rmtree(path)
... except:
... pass
>>> data = [
... LabeledPoint(0.0, SparseVector(1, {0: 0.0})),
... LabeledPoint(1.0, SparseVector(1, {0: 1.0})),
... LabeledPoint(3.0, SparseVector(1, {0: 2.0})),
... LabeledPoint(2.0, SparseVector(1, {0: 3.0}))
... ]
>>> lrm = LinearRegressionWithSGD.train(sc.parallelize(data), iterations=10,
... initialWeights=array([1.0]))
>>> abs(lrm.predict(np.array([0.0])) - 0) < 0.5
True
>>> abs(lrm.predict(SparseVector(1, {0: 1.0})) - 1) < 0.5
True
>>> lrm = RidgeRegressionWithSGD.train(sc.parallelize(data), iterations=10, step=1.0,
... regParam=0.01, miniBatchFraction=1.0, initialWeights=array([1.0]), intercept=True,
... validateData=True)
>>> abs(lrm.predict(np.array([0.0])) - 0) < 0.5
True
>>> abs(lrm.predict(SparseVector(1, {0: 1.0})) - 1) < 0.5
True
New in version 0.9.0.
Intercept computed for this model.
New in version 1.0.0.
Predict the value of the dependent variable given a vector or an RDD of vectors containing values for the independent variables.
New in version 0.9.0.
Weights computed for every feature.
New in version 1.0.0.
Train a regression model with L2-regularization using Stochastic Gradient Descent. This solves the l2-regularized least squares regression formulation
f(weights) = 1/2n ||A weights-y||^2^ + regParam/2 ||weights||^2^
Here the data matrix has n rows, and the input RDD holds the set of rows of A, each with its corresponding right hand side label y. See also the documentation for the precise formulation.
New in version 0.9.0.
Train a regression model with L2-regularization using Stochastic Gradient Descent. This solves the l2-regularized least squares regression formulation
f(weights) = 1/(2n) ||A weights - y||^2 + regParam/2 ||weights||^2.
Here the data matrix has n rows, and the input RDD holds the set of rows of A, each with its corresponding right hand side label y. See also the documentation for the precise formulation.
Parameters: |
|
---|
New in version 0.9.0.
A linear regression model derived from a least-squares fit with an l_1 penalty term.
>>> from pyspark.mllib.regression import LabeledPoint
>>> data = [
... LabeledPoint(0.0, [0.0]),
... LabeledPoint(1.0, [1.0]),
... LabeledPoint(3.0, [2.0]),
... LabeledPoint(2.0, [3.0])
... ]
>>> lrm = LassoWithSGD.train(sc.parallelize(data), iterations=10, initialWeights=array([1.0]))
>>> abs(lrm.predict(np.array([0.0])) - 0) < 0.5
True
>>> abs(lrm.predict(np.array([1.0])) - 1) < 0.5
True
>>> abs(lrm.predict(SparseVector(1, {0: 1.0})) - 1) < 0.5
True
>>> abs(lrm.predict(sc.parallelize([[1.0]])).collect()[0] - 1) < 0.5
True
>>> import os, tempfile
>>> path = tempfile.mkdtemp()
>>> lrm.save(sc, path)
>>> sameModel = LassoModel.load(sc, path)
>>> abs(sameModel.predict(np.array([0.0])) - 0) < 0.5
True
>>> abs(sameModel.predict(np.array([1.0])) - 1) < 0.5
True
>>> abs(sameModel.predict(SparseVector(1, {0: 1.0})) - 1) < 0.5
True
>>> from shutil import rmtree
>>> try:
... rmtree(path)
... except:
... pass
>>> data = [
... LabeledPoint(0.0, SparseVector(1, {0: 0.0})),
... LabeledPoint(1.0, SparseVector(1, {0: 1.0})),
... LabeledPoint(3.0, SparseVector(1, {0: 2.0})),
... LabeledPoint(2.0, SparseVector(1, {0: 3.0}))
... ]
>>> lrm = LinearRegressionWithSGD.train(sc.parallelize(data), iterations=10,
... initialWeights=array([1.0]))
>>> abs(lrm.predict(np.array([0.0])) - 0) < 0.5
True
>>> abs(lrm.predict(SparseVector(1, {0: 1.0})) - 1) < 0.5
True
>>> lrm = LassoWithSGD.train(sc.parallelize(data), iterations=10, step=1.0,
... regParam=0.01, miniBatchFraction=1.0, initialWeights=array([1.0]), intercept=True,
... validateData=True)
>>> abs(lrm.predict(np.array([0.0])) - 0) < 0.5
True
>>> abs(lrm.predict(SparseVector(1, {0: 1.0})) - 1) < 0.5
True
New in version 0.9.0.
Intercept computed for this model.
New in version 1.0.0.
Predict the value of the dependent variable given a vector or an RDD of vectors containing values for the independent variables.
New in version 0.9.0.
Weights computed for every feature.
New in version 1.0.0.
Train a regression model with L1-regularization using Stochastic Gradient Descent. This solves the l1-regularized least squares regression formulation
f(weights) = 1/2n ||A weights-y||^2^ + regParam ||weights||_1
Here the data matrix has n rows, and the input RDD holds the set of rows of A, each with its corresponding right hand side label y. See also the documentation for the precise formulation.
New in version 0.9.0.
Train a regression model with L1-regularization using Stochastic Gradient Descent. This solves the l1-regularized least squares regression formulation
f(weights) = 1/(2n) ||A weights - y||^2 + regParam ||weights||_1.
Here the data matrix has n rows, and the input RDD holds the set of rows of A, each with its corresponding right hand side label y. See also the documentation for the precise formulation.
Parameters: |
|
---|
New in version 0.9.0.
Regression model for isotonic regression.
Parameters: |
|
---|
>>> data = [(1, 0, 1), (2, 1, 1), (3, 2, 1), (1, 3, 1), (6, 4, 1), (17, 5, 1), (16, 6, 1)]
>>> irm = IsotonicRegression.train(sc.parallelize(data))
>>> irm.predict(3)
2.0
>>> irm.predict(5)
16.5
>>> irm.predict(sc.parallelize([3, 5])).collect()
[2.0, 16.5]
>>> import os, tempfile
>>> path = tempfile.mkdtemp()
>>> irm.save(sc, path)
>>> sameModel = IsotonicRegressionModel.load(sc, path)
>>> sameModel.predict(3)
2.0
>>> sameModel.predict(5)
16.5
>>> from shutil import rmtree
>>> try:
... rmtree(path)
... except OSError:
... pass
New in version 1.4.0.
Predict labels for provided features. Using a piecewise linear function. 1) If x exactly matches a boundary then associated prediction is returned. In case there are multiple predictions with the same boundary then one of them is returned. Which one is undefined (same as java.util.Arrays.binarySearch). 2) If x is lower or higher than all boundaries then first or last prediction is returned respectively. In case there are multiple predictions with the same boundary then the lowest or highest is returned respectively. 3) If x falls between two values in boundary array then prediction is treated as piecewise linear function and interpolated value is returned. In case there are multiple values with the same boundary then the same rules as in 2) are used.
Parameters: | x – Feature or RDD of Features to be labeled. |
---|
New in version 1.4.0.
Isotonic regression. Currently implemented using parallelized pool adjacent violators algorithm. Only univariate (single feature) algorithm supported.
Sequential PAV implementation based on: Tibshirani, Ryan J., Holger Hoefling, and Robert Tibshirani.
“Nearly-isotonic regression.” Technometrics 53.1 (2011): 54-61. Available from [[http://www.stat.cmu.edu/~ryantibs/papers/neariso.pdf]]
Sequential PAV parallelization based on: Kearsley, Anthony J., Richard A. Tapia, and Michael W. Trosset.
“An approach to parallelizing isotonic regression.” Applied Mathematics and Parallel Computing. Physica-Verlag HD, 1996. 141-147. Available from [[http://softlib.rice.edu/pub/CRPC-TRs/reports/CRPC-TR96640.pdf]]
:see [[http://en.wikipedia.org/wiki/Isotonic_regression Isotonic regression (Wikipedia)]]
New in version 1.4.0.
Base class that has to be inherited by any StreamingLinearAlgorithm.
Prevents reimplementation of methods predictOn and predictOnValues.
New in version 1.5.0.
Train or predict a linear regression model on streaming data. Training uses Stochastic Gradient Descent to update the model based on each new batch of incoming data from a DStream (see LinearRegressionWithSGD for model equation).
Each batch of data is assumed to be an RDD of LabeledPoints. The number of data points per batch can vary, but the number of features must be constant. An initial weight vector must be provided.
Parameters: |
|
---|
New in version 1.5.0.
Returns the latest model.
New in version 1.5.0.
Make predictions on a dstream.
Returns: | Transformed dstream object. |
---|
New in version 1.5.0.
Make predictions on a keyed dstream.
Returns: | Transformed dstream object. |
---|
New in version 1.5.0.
Python package for statistical functions in MLlib.
Note
Experimental
If observed is Vector, conduct Pearson’s chi-squared goodness of fit test of the observed data against the expected distribution, or againt the uniform distribution (by default), with each category having an expected frequency of 1 / len(observed). (Note: observed cannot contain negative values)
If observed is matrix, conduct Pearson’s independence test on the input contingency matrix, which cannot contain negative entries or columns or rows that sum up to 0.
If observed is an RDD of LabeledPoint, conduct Pearson’s independence test for every feature against the label across the input RDD. For each feature, the (feature, label) pairs are converted into a contingency matrix for which the chi-squared statistic is computed. All label and feature values must be categorical.
Parameters: |
|
---|---|
Returns: | ChiSquaredTest object containing the test statistic, degrees of freedom, p-value, the method used, and the null hypothesis. |
>>> from pyspark.mllib.linalg import Vectors, Matrices
>>> observed = Vectors.dense([4, 6, 5])
>>> pearson = Statistics.chiSqTest(observed)
>>> print(pearson.statistic)
0.4
>>> pearson.degreesOfFreedom
2
>>> print(round(pearson.pValue, 4))
0.8187
>>> pearson.method
u'pearson'
>>> pearson.nullHypothesis
u'observed follows the same distribution as expected.'
>>> observed = Vectors.dense([21, 38, 43, 80])
>>> expected = Vectors.dense([3, 5, 7, 20])
>>> pearson = Statistics.chiSqTest(observed, expected)
>>> print(round(pearson.pValue, 4))
0.0027
>>> data = [40.0, 24.0, 29.0, 56.0, 32.0, 42.0, 31.0, 10.0, 0.0, 30.0, 15.0, 12.0]
>>> chi = Statistics.chiSqTest(Matrices.dense(3, 4, data))
>>> print(round(chi.statistic, 4))
21.9958
>>> data = [LabeledPoint(0.0, Vectors.dense([0.5, 10.0])),
... LabeledPoint(0.0, Vectors.dense([1.5, 20.0])),
... LabeledPoint(1.0, Vectors.dense([1.5, 30.0])),
... LabeledPoint(0.0, Vectors.dense([3.5, 30.0])),
... LabeledPoint(0.0, Vectors.dense([3.5, 40.0])),
... LabeledPoint(1.0, Vectors.dense([3.5, 40.0])),]
>>> rdd = sc.parallelize(data, 4)
>>> chi = Statistics.chiSqTest(rdd)
>>> print(chi[0].statistic)
0.75
>>> print(chi[1].statistic)
1.5
Computes column-wise summary statistics for the input RDD[Vector].
Parameters: | rdd – an RDD[Vector] for which column-wise summary statistics are to be computed. |
---|---|
Returns: | MultivariateStatisticalSummary object containing column-wise summary statistics. |
>>> from pyspark.mllib.linalg import Vectors
>>> rdd = sc.parallelize([Vectors.dense([2, 0, 0, -2]),
... Vectors.dense([4, 5, 0, 3]),
... Vectors.dense([6, 7, 0, 8])])
>>> cStats = Statistics.colStats(rdd)
>>> cStats.mean()
array([ 4., 4., 0., 3.])
>>> cStats.variance()
array([ 4., 13., 0., 25.])
>>> cStats.count()
3
>>> cStats.numNonzeros()
array([ 3., 2., 0., 3.])
>>> cStats.max()
array([ 6., 7., 0., 8.])
>>> cStats.min()
array([ 2., 0., 0., -2.])
Compute the correlation (matrix) for the input RDD(s) using the specified method. Methods currently supported: pearson (default), spearman.
If a single RDD of Vectors is passed in, a correlation matrix comparing the columns in the input RDD is returned. Use method= to specify the method to be used for single RDD inout. If two RDDs of floats are passed in, a single float is returned.
Parameters: |
|
---|---|
Returns: | Correlation matrix comparing columns in x. |
>>> x = sc.parallelize([1.0, 0.0, -2.0], 2)
>>> y = sc.parallelize([4.0, 5.0, 3.0], 2)
>>> zeros = sc.parallelize([0.0, 0.0, 0.0], 2)
>>> abs(Statistics.corr(x, y) - 0.6546537) < 1e-7
True
>>> Statistics.corr(x, y) == Statistics.corr(x, y, "pearson")
True
>>> Statistics.corr(x, y, "spearman")
0.5
>>> from math import isnan
>>> isnan(Statistics.corr(x, zeros))
True
>>> from pyspark.mllib.linalg import Vectors
>>> rdd = sc.parallelize([Vectors.dense([1, 0, 0, -2]), Vectors.dense([4, 5, 0, 3]),
... Vectors.dense([6, 7, 0, 8]), Vectors.dense([9, 0, 0, 1])])
>>> pearsonCorr = Statistics.corr(rdd)
>>> print(str(pearsonCorr).replace('nan', 'NaN'))
[[ 1. 0.05564149 NaN 0.40047142]
[ 0.05564149 1. NaN 0.91359586]
[ NaN NaN 1. NaN]
[ 0.40047142 0.91359586 NaN 1. ]]
>>> spearmanCorr = Statistics.corr(rdd, method="spearman")
>>> print(str(spearmanCorr).replace('nan', 'NaN'))
[[ 1. 0.10540926 NaN 0.4 ]
[ 0.10540926 1. NaN 0.9486833 ]
[ NaN NaN 1. NaN]
[ 0.4 0.9486833 NaN 1. ]]
>>> try:
... Statistics.corr(rdd, "spearman")
... print("Method name as second argument without 'method=' shouldn't be allowed.")
... except TypeError:
... pass
Note
Experimental
Performs the Kolmogorov-Smirnov (KS) test for data sampled from a continuous distribution. It tests the null hypothesis that the data is generated from a particular distribution.
The given data is sorted and the Empirical Cumulative Distribution Function (ECDF) is calculated which for a given point is the number of points having a CDF value lesser than it divided by the total number of points.
Since the data is sorted, this is a step function that rises by (1 / length of data) for every ordered point.
The KS statistic gives us the maximum distance between the ECDF and the CDF. Intuitively if this statistic is large, the probabilty that the null hypothesis is true becomes small. For specific details of the implementation, please have a look at the Scala documentation.
Parameters: |
|
---|---|
Returns: | KolmogorovSmirnovTestResult object containing the test statistic, degrees of freedom, p-value, the method used, and the null hypothesis. |
>>> kstest = Statistics.kolmogorovSmirnovTest
>>> data = sc.parallelize([-1.0, 0.0, 1.0])
>>> ksmodel = kstest(data, "norm")
>>> print(round(ksmodel.pValue, 3))
1.0
>>> print(round(ksmodel.statistic, 3))
0.175
>>> ksmodel.nullHypothesis
u'Sample follows theoretical distribution'
>>> data = sc.parallelize([2.0, 3.0, 4.0])
>>> ksmodel = kstest(data, "norm", 3.0, 1.0)
>>> print(round(ksmodel.pValue, 3))
1.0
>>> print(round(ksmodel.statistic, 3))
0.175
Trait for multivariate statistical summary of a data matrix.
Contains test results for the chi-squared hypothesis test.
Name of the test method
Represents a (mu, sigma) tuple
>>> m = MultivariateGaussian(Vectors.dense([11,12]),DenseMatrix(2, 2, (1.0, 3.0, 5.0, 2.0)))
>>> (m.mu, m.sigma.toArray())
(DenseVector([11.0, 12.0]), array([[ 1., 5.],[ 3., 2.]]))
>>> (m[0], m[1])
(DenseVector([11.0, 12.0]), array([[ 1., 5.],[ 3., 2.]]))
Note
Experimental
Estimate probability density at required points given a RDD of samples from the population.
>>> kd = KernelDensity()
>>> sample = sc.parallelize([0.0, 1.0])
>>> kd.setSample(sample)
>>> kd.estimate([0.0, 1.0])
array([ 0.12938758, 0.12938758])
Estimate the probability density at points
Set bandwidth of each sample. Defaults to 1.0
Set sample points from the population. Should be a RDD
Note
Experimental
A decision tree model for classification or regression.
New in version 1.1.0.
Call method of java_model
Get depth of tree. E.g.: Depth 0 means 1 leaf node. Depth 1 means 1 internal node and 2 leaf nodes.
New in version 1.1.0.
Load a model from the given path.
New in version 1.3.0.
Predict the label of one or more examples.
Parameters: | x – Data point (feature vector), or an RDD of data points (feature vectors). |
---|
New in version 1.1.0.
Save this model to the given path.
New in version 1.3.0.
Note
Experimental
Learning algorithm for a decision tree model for classification or regression.
New in version 1.1.0.
Train a DecisionTreeModel for classification.
Parameters: |
|
---|---|
Returns: | DecisionTreeModel |
Example usage:
>>> from numpy import array
>>> from pyspark.mllib.regression import LabeledPoint
>>> from pyspark.mllib.tree import DecisionTree
>>>
>>> data = [
... LabeledPoint(0.0, [0.0]),
... LabeledPoint(1.0, [1.0]),
... LabeledPoint(1.0, [2.0]),
... LabeledPoint(1.0, [3.0])
... ]
>>> model = DecisionTree.trainClassifier(sc.parallelize(data), 2, {})
>>> print(model)
DecisionTreeModel classifier of depth 1 with 3 nodes
>>> print(model.toDebugString())
DecisionTreeModel classifier of depth 1 with 3 nodes
If (feature 0 <= 0.0)
Predict: 0.0
Else (feature 0 > 0.0)
Predict: 1.0
>>> model.predict(array([1.0]))
1.0
>>> model.predict(array([0.0]))
0.0
>>> rdd = sc.parallelize([[1.0], [0.0]])
>>> model.predict(rdd).collect()
[1.0, 0.0]
New in version 1.1.0.
Train a DecisionTreeModel for regression.
Parameters: |
|
---|---|
Returns: | DecisionTreeModel |
Example usage:
>>> from pyspark.mllib.regression import LabeledPoint
>>> from pyspark.mllib.tree import DecisionTree
>>> from pyspark.mllib.linalg import SparseVector
>>>
>>> sparse_data = [
... LabeledPoint(0.0, SparseVector(2, {0: 0.0})),
... LabeledPoint(1.0, SparseVector(2, {1: 1.0})),
... LabeledPoint(0.0, SparseVector(2, {0: 0.0})),
... LabeledPoint(1.0, SparseVector(2, {1: 2.0}))
... ]
>>>
>>> model = DecisionTree.trainRegressor(sc.parallelize(sparse_data), {})
>>> model.predict(SparseVector(2, {1: 1.0}))
1.0
>>> model.predict(SparseVector(2, {1: 0.0}))
0.0
>>> rdd = sc.parallelize([[0.0, 1.0], [0.0, 0.0]])
>>> model.predict(rdd).collect()
[1.0, 0.0]
New in version 1.1.0.
Note
Experimental
Represents a random forest model.
New in version 1.2.0.
Call method of java_model
Load a model from the given path.
New in version 1.3.0.
Get number of trees in ensemble.
New in version 1.3.0.
Predict values for a single data point or an RDD of points using the model trained.
New in version 1.3.0.
Save this model to the given path.
New in version 1.3.0.
Full model
New in version 1.3.0.
Get total number of nodes, summed over all trees in the ensemble.
New in version 1.3.0.
Note
Experimental
Learning algorithm for a random forest model for classification or regression.
New in version 1.2.0.
Method to train a decision tree model for binary or multiclass classification.
Parameters: |
|
---|---|
Returns: | RandomForestModel that can be used for prediction |
Example usage:
>>> from pyspark.mllib.regression import LabeledPoint
>>> from pyspark.mllib.tree import RandomForest
>>>
>>> data = [
... LabeledPoint(0.0, [0.0]),
... LabeledPoint(0.0, [1.0]),
... LabeledPoint(1.0, [2.0]),
... LabeledPoint(1.0, [3.0])
... ]
>>> model = RandomForest.trainClassifier(sc.parallelize(data), 2, {}, 3, seed=42)
>>> model.numTrees()
3
>>> model.totalNumNodes()
7
>>> print(model)
TreeEnsembleModel classifier with 3 trees
>>> print(model.toDebugString())
TreeEnsembleModel classifier with 3 trees
Tree 0:
Predict: 1.0
Tree 1:
If (feature 0 <= 1.0)
Predict: 0.0
Else (feature 0 > 1.0)
Predict: 1.0
Tree 2:
If (feature 0 <= 1.0)
Predict: 0.0
Else (feature 0 > 1.0)
Predict: 1.0
>>> model.predict([2.0])
1.0
>>> model.predict([0.0])
0.0
>>> rdd = sc.parallelize([[3.0], [1.0]])
>>> model.predict(rdd).collect()
[1.0, 0.0]
New in version 1.2.0.
Method to train a decision tree model for regression.
Parameters: |
|
---|---|
Returns: | RandomForestModel that can be used for prediction |
Example usage:
>>> from pyspark.mllib.regression import LabeledPoint
>>> from pyspark.mllib.tree import RandomForest
>>> from pyspark.mllib.linalg import SparseVector
>>>
>>> sparse_data = [
... LabeledPoint(0.0, SparseVector(2, {0: 1.0})),
... LabeledPoint(1.0, SparseVector(2, {1: 1.0})),
... LabeledPoint(0.0, SparseVector(2, {0: 1.0})),
... LabeledPoint(1.0, SparseVector(2, {1: 2.0}))
... ]
>>>
>>> model = RandomForest.trainRegressor(sc.parallelize(sparse_data), {}, 2, seed=42)
>>> model.numTrees()
2
>>> model.totalNumNodes()
4
>>> model.predict(SparseVector(2, {1: 1.0}))
1.0
>>> model.predict(SparseVector(2, {0: 1.0}))
0.5
>>> rdd = sc.parallelize([[0.0, 1.0], [1.0, 0.0]])
>>> model.predict(rdd).collect()
[1.0, 0.5]
New in version 1.2.0.
Note
Experimental
Represents a gradient-boosted tree model.
New in version 1.3.0.
Call method of java_model
Load a model from the given path.
New in version 1.3.0.
Get number of trees in ensemble.
New in version 1.3.0.
Predict values for a single data point or an RDD of points using the model trained.
New in version 1.3.0.
Save this model to the given path.
New in version 1.3.0.
Full model
New in version 1.3.0.
Get total number of nodes, summed over all trees in the ensemble.
New in version 1.3.0.
Note
Experimental
Learning algorithm for a gradient boosted trees model for classification or regression.
New in version 1.3.0.
Method to train a gradient-boosted trees model for classification.
Parameters: |
|
---|---|
Returns: | GradientBoostedTreesModel that can be used for prediction |
Example usage:
>>> from pyspark.mllib.regression import LabeledPoint
>>> from pyspark.mllib.tree import GradientBoostedTrees
>>>
>>> data = [
... LabeledPoint(0.0, [0.0]),
... LabeledPoint(0.0, [1.0]),
... LabeledPoint(1.0, [2.0]),
... LabeledPoint(1.0, [3.0])
... ]
>>>
>>> model = GradientBoostedTrees.trainClassifier(sc.parallelize(data), {}, numIterations=10)
>>> model.numTrees()
10
>>> model.totalNumNodes()
30
>>> print(model) # it already has newline
TreeEnsembleModel classifier with 10 trees
>>> model.predict([2.0])
1.0
>>> model.predict([0.0])
0.0
>>> rdd = sc.parallelize([[2.0], [0.0]])
>>> model.predict(rdd).collect()
[1.0, 0.0]
New in version 1.3.0.
Method to train a gradient-boosted trees model for regression.
Parameters: |
|
---|---|
Returns: | GradientBoostedTreesModel that can be used for prediction |
Example usage:
>>> from pyspark.mllib.regression import LabeledPoint
>>> from pyspark.mllib.tree import GradientBoostedTrees
>>> from pyspark.mllib.linalg import SparseVector
>>>
>>> sparse_data = [
... LabeledPoint(0.0, SparseVector(2, {0: 1.0})),
... LabeledPoint(1.0, SparseVector(2, {1: 1.0})),
... LabeledPoint(0.0, SparseVector(2, {0: 1.0})),
... LabeledPoint(1.0, SparseVector(2, {1: 2.0}))
... ]
>>>
>>> data = sc.parallelize(sparse_data)
>>> model = GradientBoostedTrees.trainRegressor(data, {}, numIterations=10)
>>> model.numTrees()
10
>>> model.totalNumNodes()
12
>>> model.predict(SparseVector(2, {1: 1.0}))
1.0
>>> model.predict(SparseVector(2, {0: 1.0}))
0.0
>>> rdd = sc.parallelize([[0.0, 1.0], [1.0, 0.0]])
>>> model.predict(rdd).collect()
[1.0, 0.0]
New in version 1.3.0.
Mixin for classes which can load saved models using its Scala implementation.
New in version 1.3.0.
Mixin for models that provide save() through their Scala implementation.
New in version 1.3.0.
Utils for generating linear data.
New in version 1.5.0.
Param: | intercept bias factor, the term c in X’w + c |
---|---|
Param: | weights feature vector, the term w in X’w + c |
Param: | xMean Point around which the data X is centered. |
Param: | xVariance Variance of the given data |
Param: | nPoints Number of points to be generated |
Param: | seed Random Seed |
Param: | eps Used to scale the noise. If eps is set high, the amount of gaussian noise added is more. |
Returns a list of LabeledPoints of length nPoints
New in version 1.5.0.
Mixin for classes which can load saved models from files.
New in version 1.3.0.
Helper methods to load, save and pre-process data used in MLlib.
New in version 1.0.0.
Returns a new vector with 1.0 (bias) appended to the end of the input vector.
New in version 1.5.0.
Load labeled points saved using RDD.saveAsTextFile.
Parameters: |
|
---|---|
Returns: | labeled data stored as an RDD of LabeledPoint |
>>> from tempfile import NamedTemporaryFile
>>> from pyspark.mllib.util import MLUtils
>>> from pyspark.mllib.regression import LabeledPoint
>>> examples = [LabeledPoint(1.1, Vectors.sparse(3, [(0, -1.23), (2, 4.56e-7)])), LabeledPoint(0.0, Vectors.dense([1.01, 2.02, 3.03]))]
>>> tempFile = NamedTemporaryFile(delete=True)
>>> tempFile.close()
>>> sc.parallelize(examples, 1).saveAsTextFile(tempFile.name)
>>> MLUtils.loadLabeledPoints(sc, tempFile.name).collect()
[LabeledPoint(1.1, (3,[0,2],[-1.23,4.56e-07])), LabeledPoint(0.0, [1.01,2.02,3.03])]
New in version 1.1.0.
Loads labeled data in the LIBSVM format into an RDD of LabeledPoint. The LIBSVM format is a text-based format used by LIBSVM and LIBLINEAR. Each line represents a labeled sparse feature vector using the following format:
label index1:value1 index2:value2 ...
where the indices are one-based and in ascending order. This method parses each line into a LabeledPoint, where the feature indices are converted to zero-based.
Parameters: |
|
---|---|
Returns: | labeled data stored as an RDD of LabeledPoint |
>>> from tempfile import NamedTemporaryFile
>>> from pyspark.mllib.util import MLUtils
>>> from pyspark.mllib.regression import LabeledPoint
>>> tempFile = NamedTemporaryFile(delete=True)
>>> _ = tempFile.write(b"+1 1:1.0 3:2.0 5:3.0\n-1\n-1 2:4.0 4:5.0 6:6.0")
>>> tempFile.flush()
>>> examples = MLUtils.loadLibSVMFile(sc, tempFile.name).collect()
>>> tempFile.close()
>>> examples[0]
LabeledPoint(1.0, (6,[0,2,4],[1.0,2.0,3.0]))
>>> examples[1]
LabeledPoint(-1.0, (6,[],[]))
>>> examples[2]
LabeledPoint(-1.0, (6,[1,3,5],[4.0,5.0,6.0]))
New in version 1.0.0.
Loads vectors saved using RDD[Vector].saveAsTextFile with the default number of partitions.
New in version 1.5.0.
Save labeled data in LIBSVM format.
Parameters: |
|
---|
>>> from tempfile import NamedTemporaryFile
>>> from fileinput import input
>>> from pyspark.mllib.regression import LabeledPoint
>>> from glob import glob
>>> from pyspark.mllib.util import MLUtils
>>> examples = [LabeledPoint(1.1, Vectors.sparse(3, [(0, 1.23), (2, 4.56)])), LabeledPoint(0.0, Vectors.dense([1.01, 2.02, 3.03]))]
>>> tempFile = NamedTemporaryFile(delete=True)
>>> tempFile.close()
>>> MLUtils.saveAsLibSVMFile(sc.parallelize(examples), tempFile.name)
>>> ''.join(sorted(input(glob(tempFile.name + "/part-0000*"))))
'0.0 1:1.01 2:2.02 3:3.03\n1.1 1:1.23 3:4.56\n'
New in version 1.0.0.
Mixin for models and transformers which may be saved as files.
New in version 1.3.0.
Save this model to the given path.
The model may be loaded using py:meth:Loader.load.
Parameters: |
|
---|