189df165bb
We should standardize the text format used to represent vectors and labeled points. The proposed formats are the following: 1. dense vector: `[v0,v1,..]` 2. sparse vector: `(size,[i0,i1],[v0,v1])` 3. labeled point: `(label,vector)` where "(..)" indicates a tuple and "[...]" indicate an array. `loadLabeledPoints` is added to pyspark's `MLUtils`. I didn't add `loadVectors` to pyspark because `RDD.saveAsTextFile` cannot stringify dense vectors in the proposed format automatically. `MLUtils#saveLabeledData` and `MLUtils#loadLabeledData` are deprecated. Users should use `RDD#saveAsTextFile` and `MLUtils#loadLabeledPoints` instead. In Scala, `MLUtils#loadLabeledPoints` is compatible with the format used by `MLUtils#loadLabeledData`. CC: @mateiz, @srowen Author: Xiangrui Meng <meng@databricks.com> Closes #685 from mengxr/labeled-io and squashes the following commits: 2d1116a [Xiangrui Meng] make loadLabeledData/saveLabeledData deprecated since 1.0.1 297be75 [Xiangrui Meng] change LabeledPoint.parse to LabeledPointParser.parse to maintain binary compatibility d6b1473 [Xiangrui Meng] Merge branch 'master' into labeled-io 56746ea [Xiangrui Meng] replace # by . 623a5f0 [Xiangrui Meng] merge master f06d5ba [Xiangrui Meng] add docs and minor updates 640fe0c [Xiangrui Meng] throw SparkException 5bcfbc4 [Xiangrui Meng] update test to add scientific notations e86bf38 [Xiangrui Meng] remove NumericTokenizer 050fca4 [Xiangrui Meng] use StringTokenizer 6155b75 [Xiangrui Meng] merge master f644438 [Xiangrui Meng] remove parse methods based on eval from pyspark a41675a [Xiangrui Meng] python loadLabeledPoint uses Scala's implementation ce9a475 [Xiangrui Meng] add deserialize_labeled_point to pyspark with tests e9fcd49 [Xiangrui Meng] add serializeLabeledPoint and tests aea4ae3 [Xiangrui Meng] minor updates 810d6df [Xiangrui Meng] update tokenizer/parser implementation 7aac03a [Xiangrui Meng] remove Scala parsers c1885c1 [Xiangrui Meng] add headers and minor changes b0c50cb [Xiangrui Meng] add customized parser d731817 [Xiangrui Meng] style update 63dc396 [Xiangrui Meng] add loadLabeledPoints to pyspark ea122b5 [Xiangrui Meng] Merge branch 'master' into labeled-io cd6c78f [Xiangrui Meng] add __str__ and parse to LabeledPoint a7a178e [Xiangrui Meng] add stringify to pyspark's Vectors 5c2dbfa [Xiangrui Meng] add parse to pyspark's Vectors 7853f88 [Xiangrui Meng] update pyspark's SparseVector.__str__ e761d32 [Xiangrui Meng] make LabelPoint.parse compatible with the dense format used before v1.0 and deprecate loadLabeledData and saveLabeledData 9e63a02 [Xiangrui Meng] add loadVectors and loadLabeledPoints 19aa523 [Xiangrui Meng] update toString and add parsers for Vectors and LabeledPoint
221 lines
8.1 KiB
Python
221 lines
8.1 KiB
Python
#
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# Licensed to the Apache Software Foundation (ASF) under one or more
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# contributor license agreements. See the NOTICE file distributed with
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# this work for additional information regarding copyright ownership.
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# The ASF licenses this file to You under the Apache License, Version 2.0
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# (the "License"); you may not use this file except in compliance with
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# the License. You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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#
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from numpy import array, ndarray
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from pyspark import SparkContext
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from pyspark.mllib._common import \
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_dot, _get_unmangled_rdd, _get_unmangled_double_vector_rdd, \
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_serialize_double_matrix, _deserialize_double_matrix, \
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_serialize_double_vector, _deserialize_double_vector, \
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_get_initial_weights, _serialize_rating, _regression_train_wrapper, \
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_linear_predictor_typecheck, _have_scipy, _scipy_issparse
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from pyspark.mllib.linalg import SparseVector, Vectors
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class LabeledPoint(object):
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"""
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The features and labels of a data point.
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@param label: Label for this data point.
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@param features: Vector of features for this point (NumPy array, list,
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pyspark.mllib.linalg.SparseVector, or scipy.sparse column matrix)
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"""
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def __init__(self, label, features):
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self.label = label
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if (type(features) == ndarray or type(features) == SparseVector
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or (_have_scipy and _scipy_issparse(features))):
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self.features = features
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elif type(features) == list:
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self.features = array(features)
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else:
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raise TypeError("Expected NumPy array, list, SparseVector, or scipy.sparse matrix")
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def __str__(self):
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return "(" + ",".join((str(self.label), Vectors.stringify(self.features))) + ")"
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class LinearModel(object):
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"""A linear model that has a vector of coefficients and an intercept."""
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def __init__(self, weights, intercept):
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self._coeff = weights
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self._intercept = intercept
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@property
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def weights(self):
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return self._coeff
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@property
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def intercept(self):
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return self._intercept
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class LinearRegressionModelBase(LinearModel):
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"""A linear regression model.
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>>> lrmb = LinearRegressionModelBase(array([1.0, 2.0]), 0.1)
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>>> abs(lrmb.predict(array([-1.03, 7.777])) - 14.624) < 1e-6
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True
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>>> abs(lrmb.predict(SparseVector(2, {0: -1.03, 1: 7.777})) - 14.624) < 1e-6
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True
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"""
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def predict(self, x):
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"""Predict the value of the dependent variable given a vector x"""
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"""containing values for the independent variables."""
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_linear_predictor_typecheck(x, self._coeff)
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return _dot(x, self._coeff) + self._intercept
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class LinearRegressionModel(LinearRegressionModelBase):
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"""A linear regression model derived from a least-squares fit.
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>>> from pyspark.mllib.regression import LabeledPoint
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>>> data = [
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... LabeledPoint(0.0, [0.0]),
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... LabeledPoint(1.0, [1.0]),
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... LabeledPoint(3.0, [2.0]),
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... LabeledPoint(2.0, [3.0])
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... ]
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>>> lrm = LinearRegressionWithSGD.train(sc.parallelize(data), initialWeights=array([1.0]))
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>>> abs(lrm.predict(array([0.0])) - 0) < 0.5
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True
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>>> abs(lrm.predict(array([1.0])) - 1) < 0.5
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True
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>>> abs(lrm.predict(SparseVector(1, {0: 1.0})) - 1) < 0.5
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True
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>>> data = [
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... LabeledPoint(0.0, SparseVector(1, {0: 0.0})),
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... LabeledPoint(1.0, SparseVector(1, {0: 1.0})),
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... LabeledPoint(3.0, SparseVector(1, {0: 2.0})),
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... LabeledPoint(2.0, SparseVector(1, {0: 3.0}))
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... ]
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>>> lrm = LinearRegressionWithSGD.train(sc.parallelize(data), initialWeights=array([1.0]))
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>>> abs(lrm.predict(array([0.0])) - 0) < 0.5
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True
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>>> abs(lrm.predict(SparseVector(1, {0: 1.0})) - 1) < 0.5
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True
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"""
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class LinearRegressionWithSGD(object):
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@classmethod
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def train(cls, data, iterations=100, step=1.0,
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miniBatchFraction=1.0, initialWeights=None):
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"""Train a linear regression model on the given data."""
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sc = data.context
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train_f = lambda d, i: sc._jvm.PythonMLLibAPI().trainLinearRegressionModelWithSGD(
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d._jrdd, iterations, step, miniBatchFraction, i)
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return _regression_train_wrapper(sc, train_f, LinearRegressionModel, data, initialWeights)
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class LassoModel(LinearRegressionModelBase):
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"""A linear regression model derived from a least-squares fit with an
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l_1 penalty term.
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>>> from pyspark.mllib.regression import LabeledPoint
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>>> data = [
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... LabeledPoint(0.0, [0.0]),
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... LabeledPoint(1.0, [1.0]),
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... LabeledPoint(3.0, [2.0]),
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... LabeledPoint(2.0, [3.0])
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... ]
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>>> lrm = LassoWithSGD.train(sc.parallelize(data), initialWeights=array([1.0]))
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>>> abs(lrm.predict(array([0.0])) - 0) < 0.5
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True
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>>> abs(lrm.predict(array([1.0])) - 1) < 0.5
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True
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>>> abs(lrm.predict(SparseVector(1, {0: 1.0})) - 1) < 0.5
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True
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>>> data = [
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... LabeledPoint(0.0, SparseVector(1, {0: 0.0})),
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... LabeledPoint(1.0, SparseVector(1, {0: 1.0})),
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... LabeledPoint(3.0, SparseVector(1, {0: 2.0})),
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... LabeledPoint(2.0, SparseVector(1, {0: 3.0}))
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... ]
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>>> lrm = LinearRegressionWithSGD.train(sc.parallelize(data), initialWeights=array([1.0]))
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>>> abs(lrm.predict(array([0.0])) - 0) < 0.5
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True
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>>> abs(lrm.predict(SparseVector(1, {0: 1.0})) - 1) < 0.5
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True
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"""
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class LassoWithSGD(object):
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@classmethod
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def train(cls, data, iterations=100, step=1.0, regParam=1.0,
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miniBatchFraction=1.0, initialWeights=None):
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"""Train a Lasso regression model on the given data."""
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sc = data.context
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train_f = lambda d, i: sc._jvm.PythonMLLibAPI().trainLassoModelWithSGD(
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d._jrdd, iterations, step, regParam, miniBatchFraction, i)
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return _regression_train_wrapper(sc, train_f, LassoModel, data, initialWeights)
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class RidgeRegressionModel(LinearRegressionModelBase):
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"""A linear regression model derived from a least-squares fit with an
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l_2 penalty term.
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>>> from pyspark.mllib.regression import LabeledPoint
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>>> data = [
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... LabeledPoint(0.0, [0.0]),
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... LabeledPoint(1.0, [1.0]),
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... LabeledPoint(3.0, [2.0]),
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... LabeledPoint(2.0, [3.0])
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... ]
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>>> lrm = RidgeRegressionWithSGD.train(sc.parallelize(data), initialWeights=array([1.0]))
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>>> abs(lrm.predict(array([0.0])) - 0) < 0.5
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True
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>>> abs(lrm.predict(array([1.0])) - 1) < 0.5
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True
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>>> abs(lrm.predict(SparseVector(1, {0: 1.0})) - 1) < 0.5
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True
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>>> data = [
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... LabeledPoint(0.0, SparseVector(1, {0: 0.0})),
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... LabeledPoint(1.0, SparseVector(1, {0: 1.0})),
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... LabeledPoint(3.0, SparseVector(1, {0: 2.0})),
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... LabeledPoint(2.0, SparseVector(1, {0: 3.0}))
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... ]
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>>> lrm = LinearRegressionWithSGD.train(sc.parallelize(data), initialWeights=array([1.0]))
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>>> abs(lrm.predict(array([0.0])) - 0) < 0.5
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True
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>>> abs(lrm.predict(SparseVector(1, {0: 1.0})) - 1) < 0.5
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True
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"""
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class RidgeRegressionWithSGD(object):
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@classmethod
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def train(cls, data, iterations=100, step=1.0, regParam=1.0,
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miniBatchFraction=1.0, initialWeights=None):
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"""Train a ridge regression model on the given data."""
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sc = data.context
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train_func = lambda d, i: sc._jvm.PythonMLLibAPI().trainRidgeModelWithSGD(
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d._jrdd, iterations, step, regParam, miniBatchFraction, i)
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return _regression_train_wrapper(sc, train_func, RidgeRegressionModel, data, initialWeights)
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def _test():
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import doctest
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globs = globals().copy()
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globs['sc'] = SparkContext('local[4]', 'PythonTest', batchSize=2)
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(failure_count, test_count) = doctest.testmod(globs=globs, optionflags=doctest.ELLIPSIS)
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globs['sc'].stop()
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if failure_count:
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exit(-1)
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if __name__ == "__main__":
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_test()
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