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paddlepaddle--paddle/test/distribution/test_distribution_lognormal.py
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2026-07-13 12:40:42 +08:00

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# Copyright (c) 2022 PaddlePaddle Authors. All Rights Reserved.
#
# Licensed 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.
import math
import unittest
import numpy as np
import scipy.stats
from distribution import config
from parameterize import TEST_CASE_NAME, parameterize_cls, place, xrand
from test_distribution import DistributionNumpy
import paddle
from paddle.distribution.kl import kl_divergence
from paddle.distribution.lognormal import LogNormal
from paddle.distribution.normal import Normal
class LogNormalNumpy(DistributionNumpy):
def __init__(self, loc, scale):
self.loc = np.array(loc)
self.scale = np.array(scale)
if str(self.loc.dtype) not in ['float32', 'float64']:
self.loc = self.loc.astype('float32')
self.scale = self.scale.astype('float32')
@property
def mean(self):
var = self.scale * self.scale
return np.exp(self.loc + var / 2)
@property
def variance(self):
var = self.scale * self.scale
return (np.exp(var) - 1) * np.exp(2 * self.loc + var)
def log_prob(self, value):
var = self.scale * self.scale
log_scale = np.log(self.scale)
return (
-((np.log(value) - self.loc) * (np.log(value) - self.loc))
/ (2.0 * var)
- log_scale
- math.log(math.sqrt(2.0 * math.pi))
- np.log(value)
)
def probs(self, value):
var = self.scale * self.scale
return np.exp(
-1.0
* ((np.log(value) - self.loc) * (np.log(value) - self.loc))
/ (2.0 * var)
) / (math.sqrt(2 * math.pi) * self.scale * value)
def entropy(self):
return (
0.5
+ self.loc
+ 0.5 * np.log(np.array(2.0 * math.pi).astype(self.loc.dtype))
+ np.log(self.scale)
)
def kl_divergence(self, other):
var_ratio = self.scale / other.scale
var_ratio = var_ratio * var_ratio
t1 = (self.loc - other.loc) / other.scale
t1 = t1 * t1
return 0.5 * (var_ratio + t1 - 1 - np.log(var_ratio))
@place(config.DEVICES)
@parameterize_cls(
(TEST_CASE_NAME, 'loc', 'scale', 'value'),
[
('one-dim', xrand((2,)), xrand((2,)), xrand((2,))),
('multi-dim', xrand((3, 3)), xrand((3, 3)), xrand((3, 3))),
],
)
class LogNormalTest(unittest.TestCase):
def setUp(self):
paddle.disable_static()
self.paddle_lognormal = LogNormal(
loc=paddle.to_tensor(self.loc), scale=paddle.to_tensor(self.scale)
)
self.np_lognormal = LogNormalNumpy(self.loc, self.scale)
def test_mean(self):
mean = self.paddle_lognormal.mean
np_mean = self.np_lognormal.mean
self.assertEqual(mean.numpy().dtype, np_mean.dtype)
np.testing.assert_allclose(
mean,
np_mean,
rtol=config.RTOL.get(str(self.scale.dtype)),
atol=config.ATOL.get(str(self.scale.dtype)),
)
def test_variance(self):
var = self.paddle_lognormal.variance
np_var = self.np_lognormal.variance
self.assertEqual(var.numpy().dtype, np_var.dtype)
np.testing.assert_allclose(
var,
np_var,
rtol=config.RTOL.get(str(self.scale.dtype)),
atol=config.ATOL.get(str(self.scale.dtype)),
)
def test_entropy(self):
entropy = self.paddle_lognormal.entropy()
np_entropy = self.np_lognormal.entropy()
self.assertEqual(entropy.numpy().dtype, np_entropy.dtype)
np.testing.assert_allclose(
entropy,
np_entropy,
rtol=config.RTOL.get(str(self.scale.dtype)),
atol=config.ATOL.get(str(self.scale.dtype)),
)
def test_probs(self):
with paddle.base.dygraph.guard(self.place):
probs = self.paddle_lognormal.probs(paddle.to_tensor(self.value))
np_probs = self.np_lognormal.probs(self.value)
np.testing.assert_allclose(
probs,
np_probs,
rtol=config.RTOL.get(str(self.scale.dtype)),
atol=config.ATOL.get(str(self.scale.dtype)),
)
def test_log_prob(self):
with paddle.base.dygraph.guard(self.place):
log_prob = self.paddle_lognormal.log_prob(
paddle.to_tensor(self.value)
)
np_log_prob = self.np_lognormal.log_prob(self.value)
np.testing.assert_allclose(
log_prob,
np_log_prob,
rtol=config.RTOL.get(str(self.scale.dtype)),
atol=config.ATOL.get(str(self.scale.dtype)),
)
@place(config.DEVICES)
@parameterize_cls(
(TEST_CASE_NAME, 'loc', 'scale'),
[('sample', xrand((4,)), xrand((4,), min=0, max=1))],
)
class TestLogNormalSample(unittest.TestCase):
def setUp(self):
paddle.disable_static()
self.paddle_lognormal = LogNormal(loc=self.loc, scale=self.scale)
n = 1000000
self.sample_shape = (n,)
self.rsample_shape = (n,)
self.samples = self.paddle_lognormal.sample(self.sample_shape)
self.rsamples = self.paddle_lognormal.rsample(self.rsample_shape)
def test_sample(self):
samples_mean = self.samples.mean(axis=0)
samples_var = self.samples.var(axis=0)
np.testing.assert_allclose(
samples_mean, self.paddle_lognormal.mean, rtol=0.1, atol=0
)
np.testing.assert_allclose(
samples_var, self.paddle_lognormal.variance, rtol=0.1, atol=0
)
rsamples_mean = self.rsamples.mean(axis=0)
rsamples_var = self.rsamples.var(axis=0)
np.testing.assert_allclose(
rsamples_mean, self.paddle_lognormal.mean, rtol=0.1, atol=0
)
np.testing.assert_allclose(
rsamples_var, self.paddle_lognormal.variance, rtol=0.1, atol=0
)
batch_shape = (self.loc + self.scale).shape
self.assertEqual(
self.samples.shape, list(self.sample_shape + batch_shape)
)
self.assertEqual(
self.rsamples.shape, list(self.rsample_shape + batch_shape)
)
for i in range(len(self.scale)):
self.assertTrue(
self._kstest(self.loc[i], self.scale[i], self.samples[:, i])
)
self.assertTrue(
self._kstest(self.loc[i], self.scale[i], self.rsamples[:, i])
)
def _kstest(self, loc, scale, samples):
# Uses the Kolmogorov-Smirnov test for goodness of fit.
ks, _ = scipy.stats.kstest(
samples, scipy.stats.lognorm(s=scale, scale=np.exp(loc)).cdf
)
return ks < 0.02
@place(config.DEVICES)
@parameterize_cls(
(TEST_CASE_NAME, 'loc1', 'scale1', 'loc2', 'scale2'),
[
('one-dim', xrand((2,)), xrand((2,)), xrand((2,)), xrand((2,))),
(
'multi-dim',
xrand((2, 2)),
xrand((2, 2)),
xrand((2, 2)),
xrand((2, 2)),
),
],
)
class TestLogNormalKL(unittest.TestCase):
def setUp(self):
paddle.disable_static()
self.ln_a = LogNormal(
loc=paddle.to_tensor(self.loc1), scale=paddle.to_tensor(self.scale1)
)
self.ln_b = LogNormal(
loc=paddle.to_tensor(self.loc2), scale=paddle.to_tensor(self.scale2)
)
self.normal_a = Normal(
loc=paddle.to_tensor(self.loc1), scale=paddle.to_tensor(self.scale1)
)
self.normal_b = Normal(
loc=paddle.to_tensor(self.loc2), scale=paddle.to_tensor(self.scale2)
)
def test_kl_divergence(self):
kl0 = self.ln_a.kl_divergence(self.ln_b)
kl1 = kl_divergence(self.ln_a, self.ln_b)
kl_normal = kl_divergence(self.normal_a, self.normal_b)
kl_formula = self._kl(self.ln_a, self.ln_b)
self.assertEqual(tuple(kl0.shape), self.scale1.shape)
self.assertEqual(tuple(kl1.shape), self.scale1.shape)
np.testing.assert_allclose(
kl0,
kl_formula,
rtol=config.RTOL.get(str(self.scale1.dtype)),
atol=config.ATOL.get(str(self.scale1.dtype)),
)
np.testing.assert_allclose(
kl1,
kl_formula,
rtol=config.RTOL.get(str(self.scale1.dtype)),
atol=config.ATOL.get(str(self.scale1.dtype)),
)
np.testing.assert_allclose(
kl_normal,
kl_formula,
rtol=config.RTOL.get(str(self.scale1.dtype)),
atol=config.ATOL.get(str(self.scale1.dtype)),
)
def _kl(self, dist1, dist2):
loc1 = np.array(dist1.loc)
loc2 = np.array(dist2.loc)
scale1 = np.array(dist1.scale)
scale2 = np.array(dist2.scale)
var_ratio = scale1 / scale2
var_ratio = var_ratio * var_ratio
t1 = (loc1 - loc2) / scale2
t1 = t1 * t1
return 0.5 * (var_ratio + t1 - 1 - np.log(var_ratio))
if __name__ == '__main__':
unittest.main()