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clone and minorly adapt python kll testing to classic quantiles
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# Licensed to the Apache Software Foundation (ASF) under one | ||
# or more contributor license agreements. See the NOTICE file | ||
# distributed with this work for additional information | ||
# regarding copyright ownership. The ASF licenses this file | ||
# to you under the Apache License, Version 2.0 (the | ||
# "License"); you may not use this file except in compliance | ||
# with the License. You may obtain a copy of the License at | ||
# | ||
# http://www.apache.org/licenses/LICENSE-2.0 | ||
# | ||
# Unless required by applicable law or agreed to in writing, | ||
# software distributed under the License is distributed on an | ||
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY | ||
# KIND, either express or implied. See the License for the | ||
# specific language governing permissions and limitations | ||
# under the License. | ||
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import unittest | ||
from datasketches import quantiles_ints_sketch, quantiles_floats_sketch, quantiles_doubles_sketch | ||
import numpy as np | ||
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class QuantilesTest(unittest.TestCase): | ||
def test_quantiles_example(self): | ||
k = 128 | ||
n = 2 ** 20 | ||
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# create a sketch and inject ~1 million N(0,1) points as an array and as a single item | ||
quantiles = quantiles_floats_sketch(k) | ||
quantiles.update(np.random.normal(size=n-1)) | ||
quantiles.update(0.0) | ||
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# 0 should be near the median | ||
self.assertAlmostEqual(0.5, quantiles.get_rank(0.0), delta=0.035) | ||
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# the median should be near 0 | ||
self.assertAlmostEqual(0.0, quantiles.get_quantile(0.5), delta=0.035) | ||
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# we also track the min/max independently from the rest of the data | ||
# which lets us know the full observed data range | ||
self.assertLessEqual(quantiles.get_min_value(), quantiles.get_quantile(0.01)) | ||
self.assertLessEqual(0.0, quantiles.get_rank(quantiles.get_min_value())) | ||
self.assertGreaterEqual(quantiles.get_max_value(), quantiles.get_quantile(0.99)) | ||
self.assertGreaterEqual(1.0, quantiles.get_rank(quantiles.get_max_value())) | ||
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# we can also extract a list of values at a time, | ||
# here the values should give us something close to [-2, -1, 0, 1, 2]. | ||
# then get the CDF, which will return something close to | ||
# the original values used in get_quantiles() | ||
# finally, can check the normalized rank error bound | ||
pts = quantiles.get_quantiles([0.0228, 0.1587, 0.5, 0.8413, 0.9772]) | ||
cdf = quantiles.get_cdf(pts) # include 1.0 at end to account for all probability mass | ||
self.assertEqual(len(cdf), len(pts)+1) | ||
err = quantiles.normalized_rank_error(False) | ||
self.assertEqual(err, quantiles_floats_sketch.get_normalized_rank_error(k, False)) | ||
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# and a few basic queries about the sketch | ||
self.assertFalse(quantiles.is_empty()) | ||
self.assertTrue(quantiles.is_estimation_mode()) | ||
self.assertEqual(quantiles.get_n(), n) | ||
self.assertEqual(quantiles.get_k(), k) | ||
self.assertLess(quantiles.get_num_retained(), n) | ||
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# merging itself will double the number of items the sketch has seen | ||
quantiles.merge(quantiles) | ||
self.assertEqual(quantiles.get_n(), 2*n) | ||
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# we can then serialize and reconstruct the sketch | ||
quantiles_bytes = quantiles.serialize() | ||
new_quantiles = quantiles.deserialize(quantiles_bytes) | ||
self.assertEqual(quantiles.get_num_retained(), new_quantiles.get_num_retained()) | ||
self.assertEqual(quantiles.get_min_value(), new_quantiles.get_min_value()) | ||
self.assertEqual(quantiles.get_max_value(), new_quantiles.get_max_value()) | ||
self.assertEqual(quantiles.get_quantile(0.7), new_quantiles.get_quantile(0.7)) | ||
self.assertEqual(quantiles.get_rank(0.0), new_quantiles.get_rank(0.0)) | ||
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def test_quantiles_ints_sketch(self): | ||
k = 128 | ||
n = 10 | ||
quantiles = quantiles_ints_sketch(k) | ||
for i in range(0, n): | ||
quantiles.update(i) | ||
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self.assertEqual(quantiles.get_min_value(), 0) | ||
self.assertEqual(quantiles.get_max_value(), n-1) | ||
self.assertEqual(quantiles.get_n(), n) | ||
self.assertFalse(quantiles.is_empty()) | ||
self.assertFalse(quantiles.is_estimation_mode()) # n < k | ||
self.assertEqual(quantiles.get_k(), k) | ||
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pmf = quantiles.get_pmf([round(n/2)]) | ||
self.assertIsNotNone(pmf) | ||
self.assertEqual(len(pmf), 2) | ||
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cdf = quantiles.get_cdf([round(n/2)]) | ||
self.assertIsNotNone(cdf) | ||
self.assertEqual(len(cdf), 2) | ||
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self.assertEqual(quantiles.get_quantile(0.5), round(n/2)) | ||
quants = quantiles.get_quantiles([0.25, 0.5, 0.75]) | ||
self.assertIsNotNone(quants) | ||
self.assertEqual(len(quants), 3) | ||
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self.assertEqual(quantiles.get_rank(round(n/2)), 0.5) | ||
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# merge self | ||
quantiles.merge(quantiles) | ||
self.assertEqual(quantiles.get_n(), 2 * n) | ||
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sk_bytes = quantiles.serialize() | ||
self.assertTrue(isinstance(quantiles_ints_sketch.deserialize(sk_bytes), quantiles_ints_sketch)) | ||
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def test_quantiles_floats_sketch(self): | ||
# already tested ints and it's templatized, so just make sure it instantiates properly | ||
k = 256 | ||
quantiles = quantiles_floats_sketch(k) | ||
self.assertTrue(quantiles.is_empty()) | ||
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def test_quantiles_doubles_sketch(self): | ||
# already tested ints and it's templatized, so just make sure it instantiates properly | ||
k = 128 | ||
quantiles = quantiles_doubles_sketch(k) | ||
self.assertTrue(quantiles.is_empty()) | ||
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if __name__ == '__main__': | ||
unittest.main() |