Import Upstream version 0.5.0+dfsg

5 files changed, 684 insertions, 0 deletions

diff --git a/silx/test/__init__.py b/silx/test/__init__.py
new file mode 100644
index 0000000..01ee8d1
--- /dev/null
+++ b/silx/test/__init__.py
@@ -0,0 +1,80 @@
+# coding: utf-8
+# /*##########################################################################
+#
+# Copyright (c) 2015-2017 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.
+#
+# ###########################################################################*/
+"""Full silx test suite.
+
+
+It is possible to disable tests depending on Qt by setting
+:envvar:`WITH_QT_TEST` environment variable to 'False'.
+It will skip all tests from :mod:`silx.test.gui`.
+"""
+
+__authors__ = ["T. Vincent"]
+__license__ = "MIT"
+__date__ = "20/04/2017"
+
+
+import logging
+import os
+import unittest
+
+
+logger = logging.getLogger(__name__)
+
+
+def suite():
+    from . import test_version
+    from . import test_resources
+    from . import test_sx
+    from ..io import test as test_io
+    from ..math import test as test_math
+    from ..image import test as test_image
+    from ..gui import test as test_gui
+    from ..utils import test as test_utils
+    from ..opencl import test as test_ocl
+    test_suite = unittest.TestSuite()
+    # test sx first cause qui tests load ipython module
+    test_suite.addTest(test_sx.suite())
+    test_suite.addTest(test_gui.suite())
+    # then test no-gui tests
+    test_suite.addTest(test_utils.suite())
+    test_suite.addTest(test_version.suite())
+    test_suite.addTest(test_resources.suite())
+    test_suite.addTest(test_utils.suite())
+    test_suite.addTest(test_io.suite())
+    test_suite.addTest(test_math.suite())
+    test_suite.addTest(test_image.suite())
+    test_suite.addTest(test_ocl.suite())
+    return test_suite
+
+
+def run_tests():
+    """Run test complete test_suite"""
+    runner = unittest.TextTestRunner()
+    if not runner.run(suite()).wasSuccessful():
+        print("Test suite failed")
+        return 1
+    else:
+        print("Test suite succeeded")
+        return 0
diff --git a/silx/test/test_resources.py b/silx/test/test_resources.py
new file mode 100644
index 0000000..9d3e277
--- /dev/null
+++ b/silx/test/test_resources.py
@@ -0,0 +1,97 @@
+# coding: utf-8
+# /*##########################################################################
+#
+# Copyright (c) 2016 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 resource files management."""
+
+__authors__ = ["T. Vincent"]
+__license__ = "MIT"
+__date__ = "20/04/2017"
+
+
+import os
+import unittest
+
+import silx.resources
+from .utils import utilstest
+
+
+class TestResources(unittest.TestCase):
+    def test_resource_dir(self):
+        """Get a resource directory"""
+        icons_dirname = silx.resources.resource_filename('gui/icons/')
+        self.assertTrue(os.path.isdir(icons_dirname))
+
+    def test_resource_file(self):
+        """Get a resource file name"""
+        filename = silx.resources.resource_filename('gui/icons/colormap.png')
+        self.assertTrue(os.path.isfile(filename))
+
+    def test_resource_nonexistent(self):
+        """Get a non existent resource"""
+        filename = silx.resources.resource_filename('non_existent_file.txt')
+        self.assertFalse(os.path.exists(filename))
+
+
+class TestExternalResources(unittest.TestCase):
+    "This is a test for the TestResources"
+    def test_tempdir(self):
+        "test the temporary directory creation"
+        myutilstest = silx.resources.ExternalResources("toto", "http://www.silx.org")
+        d = myutilstest.tempdir
+        self.assertTrue(os.path.isdir(d))
+        self.assertEqual(d, myutilstest.tempdir, 'tmpdir is stable')
+        myutilstest.clean_up()
+        self.assertFalse(os.path.isdir(d))
+        e = myutilstest.tempdir
+        self.assertTrue(os.path.isdir(e))
+        self.assertEqual(e, myutilstest.tempdir, 'tmpdir is stable')
+        self.assertNotEqual(d, e, "tempdir changed")
+        myutilstest.clean_up()
+
+    def test_download(self):
+        "test the download from silx.org"
+        f = utilstest.getfile("lena.png")
+        self.assertTrue(os.path.exists(f))
+        f = utilstest.getdir("source.tar.gz")
+        self.assertTrue(os.path.isfile(f))
+        self.assertTrue(os.path.isdir(f[:-7]))
+
+    def test_dowload_all(self):
+        "test the download of all files from silx.org"
+        l = utilstest.download_all()
+        self.assertGreater(len(l), 1, "At least 2 items were downloaded")
+
+
+def suite():
+    test_suite = unittest.TestSuite()
+    test_suite.addTest(
+        unittest.defaultTestLoader.loadTestsFromTestCase(TestResources))
+    test_suite.addTest(TestExternalResources("test_tempdir"))
+    test_suite.addTest(TestExternalResources("test_download")) # order matters !
+    test_suite.addTest(TestExternalResources("test_dowload_all"))
+    return test_suite
+
+
+if __name__ == '__main__':
+    unittest.main(defaultTest='suite')
diff --git a/silx/test/test_sx.py b/silx/test/test_sx.py
new file mode 100644
index 0000000..0de3b35
--- /dev/null
+++ b/silx/test/test_sx.py
@@ -0,0 +1,174 @@
+# coding: utf-8
+# /*##########################################################################
+#
+# Copyright (c) 2016-2017 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.
+#
+# ###########################################################################*/
+__authors__ = ["T. Vincent", "P. Knobel"]
+__license__ = "MIT"
+__date__ = "05/12/2016"
+
+
+import logging
+import os
+import sys
+import unittest
+
+import numpy
+
+
+_logger = logging.getLogger(__name__)
+
+
+if sys.platform.startswith('linux') and not os.environ.get('DISPLAY', ''):
+    # On linux and no DISPLAY available (e.g., ssh without -X)
+    _logger.warning('silx.sx tests disabled (DISPLAY env. variable not set)')
+
+    class SkipSXTest(unittest.TestCase):
+        def runTest(self):
+            self.skipTest(
+                'silx.sx tests disabled (DISPLAY env. variable not set)')
+
+    def suite():
+        suite = unittest.TestSuite()
+        suite.addTest(SkipSXTest())
+        return suite
+
+elif os.environ.get('WITH_QT_TEST', 'True') == 'False':
+    # Explicitly disabled tests
+    _logger.warning(
+        "silx.sx tests disabled (env. variable WITH_QT_TEST=False)")
+
+    class SkipSXTest(unittest.TestCase):
+        def runTest(self):
+            self.skipTest(
+                "silx.sx tests disabled (env. variable WITH_QT_TEST=False)")
+
+    def suite():
+        suite = unittest.TestSuite()
+        suite.addTest(SkipSXTest())
+        return suite
+
+else:
+    # Import here to avoid loading QT if tests are disabled
+
+    from silx.gui import qt
+    # load TestCaseQt before sx
+    from silx.gui.test.utils import TestCaseQt
+    from silx import sx
+
+    class SXTest(TestCaseQt):
+        """Test the sx module"""
+
+        def _expose_and_close(self, plot):
+            self.qWaitForWindowExposed(plot)
+            self.qapp.processEvents()
+            plot.setAttribute(qt.Qt.WA_DeleteOnClose)
+            plot.close()
+
+        def test_plot(self):
+            """Test plot function"""
+            y = numpy.random.random(100)
+            x = numpy.arange(len(y)) * 0.5
+
+            # Nothing
+            plt = sx.plot()
+            self._expose_and_close(plt)
+
+            # y
+            plt = sx.plot(y, title='y')
+            self._expose_and_close(plt)
+
+            # y, style
+            plt = sx.plot(y, 'blued ', title='y, "blued "')
+            self._expose_and_close(plt)
+
+            # x, y
+            plt = sx.plot(x, y, title='x, y')
+            self._expose_and_close(plt)
+
+            # x, y, style
+            plt = sx.plot(x, y, 'ro-', xlabel='x', title='x, y, "ro-"')
+            self._expose_and_close(plt)
+
+            # x, y, style, y
+            plt = sx.plot(x, y, 'ro-', y ** 2, xlabel='x', ylabel='y',
+                          title='x, y, "ro-", y ** 2')
+            self._expose_and_close(plt)
+
+            # x, y, style, y, style
+            plt = sx.plot(x, y, 'ro-', y ** 2, 'b--',
+                          title='x, y, "ro-", y ** 2, "b--"')
+            self._expose_and_close(plt)
+
+            # x, y, style, x, y, style
+            plt = sx.plot(x, y, 'ro-', x, y ** 2, 'b--',
+                          title='x, y, "ro-", x, y ** 2, "b--"')
+            self._expose_and_close(plt)
+
+            # x, y, x, y
+            plt = sx.plot(x, y, x, y ** 2, title='x, y, x, y ** 2')
+            self._expose_and_close(plt)
+
+        def test_imshow(self):
+            """Test imshow function"""
+            img = numpy.arange(100.).reshape(10, 10) + 1
+
+            # Nothing
+            plt = sx.imshow()
+            self._expose_and_close(plt)
+
+            # image
+            plt = sx.imshow(img)
+            self._expose_and_close(plt)
+
+            # image, gray cmap
+            plt = sx.imshow(img, cmap='jet', title='jet cmap')
+            self._expose_and_close(plt)
+
+            # image, log cmap
+            plt = sx.imshow(img, norm='log', title='log cmap')
+            self._expose_and_close(plt)
+
+            # image, fixed range
+            plt = sx.imshow(img, vmin=10, vmax=20,
+                            title='[10,20] cmap')
+            self._expose_and_close(plt)
+
+            # image, keep ratio
+            plt = sx.imshow(img, aspect=True,
+                            title='keep ratio')
+            self._expose_and_close(plt)
+
+            # image, change origin and scale
+            plt = sx.imshow(img, origin=(10, 10), scale=(2, 2),
+                            title='origin=(10, 10), scale=(2, 2)')
+            self._expose_and_close(plt)
+
+    def suite():
+        test_suite = unittest.TestSuite()
+        test_suite.addTest(
+            unittest.defaultTestLoader.loadTestsFromTestCase(SXTest))
+        return test_suite
+
+
+if __name__ == '__main__':
+    unittest.main(defaultTest='suite')
diff --git a/silx/test/test_version.py b/silx/test/test_version.py
new file mode 100644
index 0000000..bb91e4e
--- /dev/null
+++ b/silx/test/test_version.py
@@ -0,0 +1,49 @@
+# coding: utf-8
+# /*##########################################################################
+#
+# Copyright (c) 2015-2016 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.
+#
+# ###########################################################################*/
+"""Basic test of top-level package import and existence of version info."""
+
+__authors__ = ["T. Vincent"]
+__license__ = "MIT"
+__date__ = "26/02/2016"
+
+import unittest
+
+import silx
+
+
+class TestVersion(unittest.TestCase):
+    def test_version(self):
+        self.assertTrue(isinstance(silx.version, str))
+
+
+def suite():
+    test_suite = unittest.TestSuite()
+    test_suite.addTest(
+        unittest.defaultTestLoader.loadTestsFromTestCase(TestVersion))
+    return test_suite
+
+
+if __name__ == '__main__':
+    unittest.main(defaultTest='suite')
diff --git a/silx/test/utils.py b/silx/test/utils.py
new file mode 100644
index 0000000..ec86a2a
--- /dev/null
+++ b/silx/test/utils.py
@@ -0,0 +1,284 @@
+# coding: utf-8
+# /*##########################################################################
+#
+# Copyright (c) 2016 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.
+#
+# ###########################################################################*/
+"""Utilities for writing tests.
+
+- :class:`ParametricTestCase` provides a :meth:`TestCase.subTest` replacement
+  for Python < 3.4
+- :class:`TestLogging` with context or the :func:`test_logging` decorator
+  enables testing the number of logging messages of different levels.
+- :func:`temp_dir` provides a with context to create/delete a temporary
+  directory.
+"""
+
+__authors__ = ["T. Vincent"]
+__license__ = "MIT"
+__date__ = "20/04/2017"
+
+
+import os
+import contextlib
+import functools
+import logging
+import numpy
+import shutil
+import sys
+import tempfile
+import unittest
+from ..resources import ExternalResources
+
+logger = logging.getLogger(__name__)
+
+utilstest = ExternalResources(project="silx",
+                              url_base="http://www.silx.org/pub/silx/",
+                              env_key="SILX_DATA",
+                              timeout=60)
+"This is the instance to be used. Singleton-like feature provided by module"
+
+# Parametric Test Base Class ##################################################
+
+if sys.hexversion >= 0x030400F0:  # Python >= 3.4
+    class ParametricTestCase(unittest.TestCase):
+        pass
+
+else:
+    class ParametricTestCase(unittest.TestCase):
+        """TestCase with subTest support for Python < 3.4.
+
+        Add subTest method to support parametric tests.
+        API is the same, but behavior differs:
+        If a subTest fails, the following ones are not run.
+        """
+
+        _subtest_msg = None  # Class attribute to provide a default value
+
+        @contextlib.contextmanager
+        def subTest(self, msg=None, **params):
+            """Use as unittest.TestCase.subTest method in Python >= 3.4."""
+            # Format arguments as: '[msg] (key=value, ...)'
+            param_str = ', '.join(['%s=%s' % (k, v) for k, v in params.items()])
+            self._subtest_msg = '[%s] (%s)' % (msg or '', param_str)
+            yield
+            self._subtest_msg = None
+
+        def shortDescription(self):
+            short_desc = super(ParametricTestCase, self).shortDescription()
+            if self._subtest_msg is not None:
+                # Append subTest message to shortDescription
+                short_desc = ' '.join(
+                    [msg for msg in (short_desc, self._subtest_msg) if msg])
+
+            return short_desc if short_desc else None
+
+
+# Test logging messages #######################################################
+
+class TestLogging(logging.Handler):
+    """Context checking the number of logging messages from a specified Logger.
+
+    It disables propagation of logging message while running.
+
+    This is meant to be used as a with statement, for example:
+
+    >>> with TestLogging(logger, error=2, warning=0):
+    >>>     pass  # Run tests here expecting 2 ERROR and no WARNING from logger
+    ...
+
+    :param logger: Name or instance of the logger to test.
+                   (Default: root logger)
+    :type logger: str or :class:`logging.Logger`
+    :param int critical: Expected number of CRITICAL messages.
+                         Default: Do not check.
+    :param int error: Expected number of ERROR messages.
+                      Default: Do not check.
+    :param int warning: Expected number of WARNING messages.
+                        Default: Do not check.
+    :param int info: Expected number of INFO messages.
+                     Default: Do not check.
+    :param int debug: Expected number of DEBUG messages.
+                      Default: Do not check.
+    :param int notset: Expected number of NOTSET messages.
+                       Default: Do not check.
+    :raises RuntimeError: If the message counts are the expected ones.
+    """
+
+    def __init__(self, logger=None, critical=None, error=None,
+                 warning=None, info=None, debug=None, notset=None):
+        if logger is None:
+            logger = logging.getLogger()
+        elif not isinstance(logger, logging.Logger):
+            logger = logging.getLogger(logger)
+        self.logger = logger
+
+        self.records = []
+
+        self.count_by_level = {
+            logging.CRITICAL: critical,
+            logging.ERROR: error,
+            logging.WARNING: warning,
+            logging.INFO: info,
+            logging.DEBUG: debug,
+            logging.NOTSET: notset
+        }
+
+        super(TestLogging, self).__init__()
+
+    def __enter__(self):
+        """Context (i.e., with) support"""
+        self.records = []  # Reset recorded LogRecords
+        self.logger.addHandler(self)
+        self.logger.propagate = False
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        """Context (i.e., with) support"""
+        self.logger.removeHandler(self)
+        self.logger.propagate = True
+
+        for level, expected_count in self.count_by_level.items():
+            if expected_count is None:
+                continue
+
+            # Number of records for the specified level_str
+            count = len([r for r in self.records if r.levelno == level])
+            if count != expected_count:  # That's an error
+                # Resend record logs through logger as they where masked
+                # to help debug
+                for record in self.records:
+                    self.logger.handle(record)
+                raise RuntimeError(
+                    'Expected %d %s logging messages, got %d' % (
+                        expected_count, logging.getLevelName(level), count))
+
+    def emit(self, record):
+        """Override :meth:`logging.Handler.emit`"""
+        self.records.append(record)
+
+
+def test_logging(logger=None, critical=None, error=None,
+                 warning=None, info=None, debug=None, notset=None):
+    """Decorator checking number of logging messages.
+
+    Propagation of logging messages is disabled by this decorator.
+
+    In case the expected number of logging messages is not found, it raises
+    a RuntimeError.
+
+    >>> class Test(unittest.TestCase):
+    ...     @test_logging('module_logger_name', error=2, warning=0)
+    ...     def test(self):
+    ...         pass  # Test expecting 2 ERROR and 0 WARNING messages
+
+    :param logger: Name or instance of the logger to test.
+                   (Default: root logger)
+    :type logger: str or :class:`logging.Logger`
+    :param int critical: Expected number of CRITICAL messages.
+                         Default: Do not check.
+    :param int error: Expected number of ERROR messages.
+                      Default: Do not check.
+    :param int warning: Expected number of WARNING messages.
+                        Default: Do not check.
+    :param int info: Expected number of INFO messages.
+                     Default: Do not check.
+    :param int debug: Expected number of DEBUG messages.
+                      Default: Do not check.
+    :param int notset: Expected number of NOTSET messages.
+                       Default: Do not check.
+    """
+    def decorator(func):
+        test_context = TestLogging(logger, critical, error,
+                                   warning, info, debug, notset)
+
+        @functools.wraps(func)
+        def wrapper(*args, **kwargs):
+            with test_context:
+                result = func(*args, **kwargs)
+            return result
+        return wrapper
+    return decorator
+
+
+
+
+
+
+# Temporary directory context #################################################
+
+@contextlib.contextmanager
+def temp_dir():
+    """with context providing a temporary directory.
+
+    >>> import os.path
+    >>> with temp_dir() as tmp:
+    ...     print(os.path.isdir(tmp))  # Use tmp directory
+    """
+    tmp_dir = tempfile.mkdtemp()
+    try:
+        yield tmp_dir
+    finally:
+        shutil.rmtree(tmp_dir)
+
+
+# Synthetic data and random noise #############################################
+def add_gaussian_noise(y, stdev=1., mean=0.):
+    """Add random gaussian noise to synthetic data.
+
+    :param ndarray y: Array of synthetic data
+    :param float mean: Mean of the gaussian distribution of noise.
+    :param float stdev: Standard deviation of the gaussian distribution of
+        noise.
+    :return: Array of data with noise added
+    """
+    noise = numpy.random.normal(mean, stdev, size=y.size)
+    noise.shape = y.shape
+    return y + noise
+
+
+def add_poisson_noise(y):
+    """Add random noise from a poisson distribution to synthetic data.
+
+    :param ndarray y: Array of synthetic data
+    :return: Array of data with noise added
+    """
+    yn = numpy.random.poisson(y)
+    yn.shape = y.shape
+    return yn
+
+
+def add_relative_noise(y, max_noise=5.):
+    """Add relative random noise to synthetic data. The maximum noise level
+    is given in percents.
+
+    An array of noise in the interval [-max_noise, max_noise] (continuous
+    uniform distribution) is generated, and applied to the data the
+    following way:
+
+    :math:`yn = y * (1. + noise / 100.)`
+
+    :param ndarray y: Array of synthetic data
+    :param float max_noise: Maximum percentage of noise
+    :return: Array of data with noise added
+    """
+    noise = max_noise * (2 * numpy.random.random(size=y.size) - 1)
+    noise.shape = y.shape
+    return y * (1. + noise / 100.)