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Diffstat (limited to 'silx/math/test/test_colormap.py')
-rw-r--r-- | silx/math/test/test_colormap.py | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/silx/math/test/test_colormap.py b/silx/math/test/test_colormap.py new file mode 100644 index 0000000..ede7d8d --- /dev/null +++ b/silx/math/test/test_colormap.py @@ -0,0 +1,190 @@ +# coding: utf-8 +# /*########################################################################## +# +# Copyright (c) 2018 European Synchrotron Radiation Facility +# +# Permission is hereby granted, free of charge, to any person obtaining a copy +# of this software and associated documentation files (the "Software"), to deal +# in the Software without restriction, including without limitation the rights +# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +# copies of the Software, and to permit persons to whom the Software is +# furnished to do so, subject to the following conditions: +# +# The above copyright notice and this permission notice shall be included in +# all copies or substantial portions of the Software. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +# THE SOFTWARE. +# +# ############################################################################*/ +"""Test for colormap mapping implementation""" + +from __future__ import division + +__authors__ = ["T. Vincent"] +__license__ = "MIT" +__date__ = "16/05/2018" + + +import logging +import sys +import unittest + +import numpy + +from silx.utils.testutils import ParametricTestCase +from silx.math import colormap + + +_logger = logging.getLogger(__name__) + + +class TestColormap(ParametricTestCase): + """Test silx.image.colormap.cmap""" + + NORMALIZATIONS = 'linear', 'log', 'arcsinh', 'sqrt' + + @staticmethod + def ref_colormap(data, colors, vmin, vmax, normalization, nan_color): + """Reference implementation of colormap + + :param numpy.ndarray data: Data to convert + :param numpy.ndarray colors: Color look-up-table + :param float vmin: Lower bound of the colormap range + :param float vmax: Upper bound of the colormap range + :param str normalization: Normalization to use + :param Union[numpy.ndarray, None] nan_color: Color to use for NaN + """ + norm_functions = {'linear': lambda v: v, + 'log': numpy.log10, + 'arcsinh': numpy.arcsinh, + 'sqrt': numpy.sqrt} + + norm_function = norm_functions[normalization] + norm_data, vmin, vmax = map(norm_function, (data, vmin, vmax)) + + if normalization == 'arcsinh' and sys.platform == 'win32': + # There is a difference of behavior of numpy.arcsinh + # between Windows and other OS for results of infinite values + # This makes Windows behaves as Linux and MacOS + norm_data[data == numpy.inf] = numpy.inf + norm_data[data == -numpy.inf] = -numpy.inf + + nb_colors = len(colors) + scale = nb_colors / (vmax - vmin) + + # Substraction must be done in float to avoid overflow with uint + indices = numpy.clip(scale * (norm_data - float(vmin)), + 0, nb_colors - 1) + indices[numpy.isnan(indices)] = nb_colors # Use an extra index for NaN + indices = indices.astype('uint') + + # Add NaN color to array + if nan_color is None: + nan_color = (0,) * colors.shape[-1] + colors = numpy.append(colors, numpy.atleast_2d(nan_color), axis=0) + + return colors[indices] + + def _test(self, data, colors, vmin, vmax, normalization, nan_color): + """Run test of colormap against alternative implementation + + :param numpy.ndarray data: Data to convert + :param numpy.ndarray colors: Color look-up-table + :param float vmin: Lower bound of the colormap range + :param float vmax: Upper bound of the colormap range + :param str normalization: Normalization to use + :param Union[numpy.ndarray, None] nan_color: Color to use for NaN + """ + image = colormap.cmap( + data, colors, vmin, vmax, normalization, nan_color) + + ref_image = self.ref_colormap( + data, colors, vmin, vmax, normalization, nan_color) + + self.assertTrue(numpy.allclose(ref_image, image)) + self.assertEqual(image.dtype, colors.dtype) + self.assertEqual(image.shape, data.shape + (colors.shape[-1],)) + + def test(self): + """Test all dtypes with finite data + + Test all supported types and endianness + """ + colors = numpy.zeros((256, 4), dtype=numpy.uint8) + colors[:, 0] = numpy.arange(len(colors)) + colors[:, 3] = 255 + + # Generates (u)int and floats types + dtypes = [e + k + i for e in '<>' for k in 'uif' for i in '1248' + if k != 'f' or i != '1'] + dtypes.append(numpy.dtype(numpy.longdouble).name) # Add long double + + for normalization in self.NORMALIZATIONS: + for dtype in dtypes: + with self.subTest(dtype=dtype, normalization=normalization): + _logger.info('normalization: %s, dtype: %s', + normalization, dtype) + data = numpy.arange(-5, 15, dtype=dtype).reshape(4, 5) + + self._test(data, colors, 1, 10, normalization, None) + + def test_not_finite(self): + """Test float data with not finite values""" + colors = numpy.zeros((256, 4), dtype=numpy.uint8) + colors[:, 0] = numpy.arange(len(colors)) + colors[:, 3] = 255 + + test_data = { # message: data + 'no finite values': (float('inf'), float('-inf'), float('nan')), + 'only NaN': (float('nan'), float('nan'), float('nan')), + 'mix finite/not finite': (float('inf'), float('-inf'), 1., float('nan')), + } + + for normalization in self.NORMALIZATIONS: + for msg, data in test_data.items(): + with self.subTest(msg, normalization=normalization): + _logger.info('normalization: %s, %s', normalization, msg) + data = numpy.array(data, dtype=numpy.float64) + self._test(data, colors, 1, 10, normalization, (0, 0, 0, 0)) + + def test_errors(self): + """Test raising exception for bad vmin, vmax, normalization parameters + """ + colors = numpy.zeros((256, 4), dtype=numpy.uint8) + colors[:, 0] = numpy.arange(len(colors)) + colors[:, 3] = 255 + + data = numpy.arange(10, dtype=numpy.float64) + + test_params = [ # (vmin, vmax, normalization) + (-1., 2., 'log'), + (0., 1., 'log'), + (1., 0., 'log'), + (-1., 1., 'sqrt'), + (1., -1., 'sqrt'), + ] + + for vmin, vmax, normalization in test_params: + with self.subTest( + vmin=vmin, vmax=vmax, normalization=normalization): + _logger.info('normalization: %s, range: [%f, %f]', + normalization, vmin, vmax) + with self.assertRaises(ValueError): + self._test(data, colors, vmin, vmax, normalization, None) + + +def suite(): + test_suite = unittest.TestSuite() + test_suite.addTest( + unittest.defaultTestLoader.loadTestsFromTestCase(TestColormap)) + return test_suite + + +if __name__ == '__main__': + unittest.main(defaultTest='suite') |