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author | MechCoder <manojkumarsivaraj334@gmail.com> | 2015-07-28 15:00:25 -0700 |
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committer | Xiangrui Meng <meng@databricks.com> | 2015-07-28 15:00:25 -0700 |
commit | 198d181dfb2c04102afe40680a4637d951e92c0b (patch) | |
tree | 2c04e7e9bc11c8f6e5bd998919f455f148b2277d /python | |
parent | b88b868eb378bdb7459978842b5572a0b498f412 (diff) | |
download | spark-198d181dfb2c04102afe40680a4637d951e92c0b.tar.gz spark-198d181dfb2c04102afe40680a4637d951e92c0b.tar.bz2 spark-198d181dfb2c04102afe40680a4637d951e92c0b.zip |
[SPARK-7105] [PYSPARK] [MLLIB] Support model save/load in GMM
This PR introduces save / load for GMM's in python API.
Also I refactored `GaussianMixtureModel` and inherited it from `JavaModelWrapper` with model being `GaussianMixtureModelWrapper`, a wrapper which provides convenience methods to `GaussianMixtureModel` (due to serialization and deserialization issues) and I moved the creation of gaussians to the scala backend.
Author: MechCoder <manojkumarsivaraj334@gmail.com>
Closes #7617 from MechCoder/python_gmm_save_load and squashes the following commits:
9c305aa [MechCoder] [SPARK-7105] [PySpark] [MLlib] Support model save/load in GMM
Diffstat (limited to 'python')
-rw-r--r-- | python/pyspark/mllib/clustering.py | 75 | ||||
-rw-r--r-- | python/pyspark/mllib/util.py | 6 |
2 files changed, 59 insertions, 22 deletions
diff --git a/python/pyspark/mllib/clustering.py b/python/pyspark/mllib/clustering.py index 58ad99d46e..900ade248c 100644 --- a/python/pyspark/mllib/clustering.py +++ b/python/pyspark/mllib/clustering.py @@ -152,11 +152,19 @@ class KMeans(object): return KMeansModel([c.toArray() for c in centers]) -class GaussianMixtureModel(object): +@inherit_doc +class GaussianMixtureModel(JavaModelWrapper, JavaSaveable, JavaLoader): + + """ + .. note:: Experimental - """A clustering model derived from the Gaussian Mixture Model method. + 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)) @@ -169,6 +177,25 @@ class GaussianMixtureModel(object): 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, @@ -182,25 +209,15 @@ class GaussianMixtureModel(object): True >>> labels[3]==labels[4] True - >>> clusterdata_3 = sc.parallelize(data.reshape(15, 1)) - >>> im = GaussianMixtureModel([0.5, 0.5], - ... [MultivariateGaussian(Vectors.dense([-1.0]), DenseMatrix(1, 1, [1.0])), - ... MultivariateGaussian(Vectors.dense([1.0]), DenseMatrix(1, 1, [1.0]))]) - >>> model = GaussianMixture.train(clusterdata_3, 2, initialModel=im) """ - def __init__(self, weights, gaussians): - self._weights = weights - self._gaussians = gaussians - self._k = len(self._weights) - @property def weights(self): """ Weights for each Gaussian distribution in the mixture, where weights[i] is the weight for Gaussian i, and weights.sum == 1. """ - return self._weights + return array(self.call("weights")) @property def gaussians(self): @@ -208,12 +225,14 @@ class GaussianMixtureModel(object): Array of MultivariateGaussian where gaussians[i] represents the Multivariate Gaussian (Normal) Distribution for Gaussian i. """ - return self._gaussians + return [ + MultivariateGaussian(gaussian[0], gaussian[1]) + for gaussian in zip(*self.call("gaussians"))] @property def k(self): """Number of gaussians in mixture.""" - return self._k + return len(self.weights) def predict(self, x): """ @@ -238,17 +257,30 @@ class GaussianMixtureModel(object): :return: membership_matrix. RDD of array of double values. """ if isinstance(x, RDD): - means, sigmas = zip(*[(g.mu, g.sigma) for g in self._gaussians]) + means, sigmas = zip(*[(g.mu, g.sigma) for g in self.gaussians]) membership_matrix = callMLlibFunc("predictSoftGMM", x.map(_convert_to_vector), - _convert_to_vector(self._weights), means, sigmas) + _convert_to_vector(self.weights), means, sigmas) return membership_matrix.map(lambda x: pyarray.array('d', x)) else: raise TypeError("x should be represented by an RDD, " "but got %s." % type(x)) + @classmethod + def load(cls, sc, path): + """Load the GaussianMixtureModel from disk. + + :param sc: SparkContext + :param path: str, path to where the model is stored. + """ + model = cls._load_java(sc, path) + wrapper = sc._jvm.GaussianMixtureModelWrapper(model) + return cls(wrapper) + class GaussianMixture(object): """ + .. note:: Experimental + Learning algorithm for Gaussian Mixtures using the expectation-maximization algorithm. :param data: RDD of data points @@ -271,11 +303,10 @@ class GaussianMixture(object): initialModelWeights = initialModel.weights initialModelMu = [initialModel.gaussians[i].mu for i in range(initialModel.k)] initialModelSigma = [initialModel.gaussians[i].sigma for i in range(initialModel.k)] - weight, mu, sigma = callMLlibFunc("trainGaussianMixtureModel", rdd.map(_convert_to_vector), - k, convergenceTol, maxIterations, seed, - initialModelWeights, initialModelMu, initialModelSigma) - mvg_obj = [MultivariateGaussian(mu[i], sigma[i]) for i in range(k)] - return GaussianMixtureModel(weight, mvg_obj) + java_model = callMLlibFunc("trainGaussianMixtureModel", rdd.map(_convert_to_vector), + k, convergenceTol, maxIterations, seed, + initialModelWeights, initialModelMu, initialModelSigma) + return GaussianMixtureModel(java_model) class PowerIterationClusteringModel(JavaModelWrapper, JavaSaveable, JavaLoader): diff --git a/python/pyspark/mllib/util.py b/python/pyspark/mllib/util.py index 875d3b2d64..916de2d6fc 100644 --- a/python/pyspark/mllib/util.py +++ b/python/pyspark/mllib/util.py @@ -21,7 +21,9 @@ import warnings if sys.version > '3': xrange = range + basestring = str +from pyspark import SparkContext from pyspark.mllib.common import callMLlibFunc, inherit_doc from pyspark.mllib.linalg import Vectors, SparseVector, _convert_to_vector @@ -223,6 +225,10 @@ class JavaSaveable(Saveable): """ def save(self, sc, path): + if not isinstance(sc, SparkContext): + raise TypeError("sc should be a SparkContext, got type %s" % type(sc)) + if not isinstance(path, basestring): + raise TypeError("path should be a basestring, got type %s" % type(path)) self._java_model.save(sc._jsc.sc(), path) |