5aa804f3c6
Python API for KernelDensity Author: MechCoder <manojkumarsivaraj334@gmail.com> Closes #6387 from MechCoder/spark-7639 and squashes the following commits: 17abc62 [MechCoder] add tests 2de6540 [MechCoder] style tests bf4acc0 [MechCoder] Added doctests 84359d5 [MechCoder] [SPARK-7639] Python API for KernelDensity
62 lines
2 KiB
Python
62 lines
2 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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import sys
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if sys.version > '3':
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xrange = range
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import numpy as np
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from pyspark.mllib.common import callMLlibFunc
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from pyspark.rdd import RDD
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class KernelDensity(object):
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"""
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.. note:: Experimental
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Estimate probability density at required points given a RDD of samples
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from the population.
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>>> kd = KernelDensity()
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>>> sample = sc.parallelize([0.0, 1.0])
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>>> kd.setSample(sample)
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>>> kd.estimate([0.0, 1.0])
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array([ 0.12938758, 0.12938758])
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"""
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def __init__(self):
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self._bandwidth = 1.0
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self._sample = None
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def setBandwidth(self, bandwidth):
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"""Set bandwidth of each sample. Defaults to 1.0"""
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self._bandwidth = bandwidth
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def setSample(self, sample):
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"""Set sample points from the population. Should be a RDD"""
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if not isinstance(sample, RDD):
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raise TypeError("samples should be a RDD, received %s" % type(sample))
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self._sample = sample
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def estimate(self, points):
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"""Estimate the probability density at points"""
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points = list(points)
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densities = callMLlibFunc(
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"estimateKernelDensity", self._sample, self._bandwidth, points)
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return np.asarray(densities)
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