Merge pull request mantidproject#36457 from mantidproject/ewm2941_ass…

…ert_almost_equal

Add mantid.testing.assert_almost_equal

Framework/PythonInterface/mantid/_testing/AssertAlmostEqual.py

@@ -0,0 +1,48 @@
+# Mantid Repository : https://github.com/mantidproject/mantid
+#
+# Copyright © 2023 ISIS Rutherford Appleton Laboratory UKRI,
+#   NScD Oak Ridge National Laboratory, European Spallation Source,
+#   Institut Laue - Langevin & CSNS, Institute of High Energy Physics, CAS
+# SPDX - License - Identifier: GPL - 3.0 +
+
+from mantid.simpleapi import CompareWorkspaces
+
+
+def assert_almost_equal(Workspace1, Workspace2, rtol=0.0, atol=0.0):
+    """
+    Raises an assertion error if two workspaces are not within specified tolerance.
+
+    Parameters
+    ----------
+    Workspace1, Workspace2 : Workspace
+        Input workspaces to compare.
+    rtol : float
+        The relative tolerance parameter.
+    atol : float
+        The absolute tolerance parameter.
+
+    Raises
+    -------
+    AssertionError
+        If Workspace1 and Workspace2 are not equal up to specified precision
+    ValueError
+        If atol and rtol are both provided
+
+    """
+
+    if rtol != 0.0 and atol != 0.0:
+        raise ValueError("Specify rtol or atol, not both")
+    _rel = False
+    tolerance = 1e-10
+    if atol:
+        tolerance = atol
+
+    if rtol:
+        tolerance = rtol
+        _rel = True
+
+    result, message = CompareWorkspaces(Workspace1, Workspace2, Tolerance=tolerance, ToleranceRelErr=_rel)
+    msg_dict = message.toDict()
+    if not result:
+        msg = ", ".join(msg_dict["Message"]) + f", Workspaces are not within tolerance ({tolerance})"
+        raise AssertionError(msg)

Framework/PythonInterface/mantid/testing.py

@@ -0,0 +1,3 @@
+from mantid._testing.AssertAlmostEqual import assert_almost_equal
+
+__all__ = ["assert_almost_equal"]

Framework/PythonInterface/test/python/mantid/CMakeLists.txt

@@ -6,6 +6,7 @@ add_subdirectory(dataobjects)
 add_subdirectory(plots)
 add_subdirectory(utils)
 add_subdirectory(_plugins)
+add_subdirectory(_testing)
 
 set(TEST_PY_FILES ImportModuleTest.py SimpleAPITest.py SimpleAPILoadTest.py SimpleAPIFitTest.py
                   SimpleAPIRenameWorkspaceTest.py FitFunctionsTest.py

Framework/PythonInterface/test/python/mantid/_testing/AssertAlmostEqualTest.py

@@ -0,0 +1,44 @@
+# Mantid Repository : https://github.com/mantidproject/mantid
+#
+# Copyright © 2023 ISIS Rutherford Appleton Laboratory UKRI,
+#   NScD Oak Ridge National Laboratory, European Spallation Source,
+#   Institut Laue - Langevin & CSNS, Institute of High Energy Physics, CAS
+# SPDX - License - Identifier: GPL - 3.0 +
+
+import unittest
+from unittest import mock
+from mantid.testing import assert_almost_equal
+from mantid.simpleapi import CreateWorkspace
+
+
+class AssertAlmostEqualTest(unittest.TestCase):
+    @classmethod
+    def setUpClass(self):
+        ws1 = CreateWorkspace(DataX=[0, 1, 2, 3, 4, 5], DataY=[1, 1, 1, 1, 1, 1])
+        ws2 = CreateWorkspace(DataX=[0.09, 1.09, 2.09, 3.09, 4.09, 5.09], DataY=[1, 1, 1, 1, 1, 1])
+        ws3 = CreateWorkspace(DataX=[0, 2, 4, 6, 8, 10], DataY=[1, 1, 1, 1, 1, 1])
+        self.ws1 = ws1
+        self.ws2 = ws2
+        self.ws3 = ws3
+
+    def test_simple(self):
+        assert_almost_equal(self.ws1, self.ws1)
+
+    def test_atol(self):
+        # compare (ws1 - ws2) < atol
+        assert_almost_equal(self.ws1, self.ws2, atol=0.1)
+
+    def test_rtol(self):
+        # compare (ws1 - ws2) / (0.5 * (ws1 + ws2)) < rtol
+        assert_almost_equal(self.ws1, self.ws3, rtol=0.7)
+
+    def test_raises(self):
+        with self.assertRaises(AssertionError):
+            assert_almost_equal(self.ws1, self.ws2)
+
+        with self.assertRaises(ValueError):
+            assert_almost_equal(self.ws1, self.ws2, atol=1, rtol=1)
+
+
+if __name__ == "__main__":
+    unittest.main()

Framework/PythonInterface/test/python/mantid/_testing/CMakeLists.txt

@@ -0,0 +1,8 @@
+# mantid._testing tests
+
+set(TEST_PY_FILES AssertAlmostEqualTest.py)
+
+check_tests_valid(${CMAKE_CURRENT_SOURCE_DIR} ${TEST_PY_FILES})
+
+# Prefix for test=PythonInterfaceTesting
+pyunittest_add_test(${CMAKE_CURRENT_SOURCE_DIR} python._testing ${TEST_PY_FILES})

docs/source/api/python/mantid/index.rst

@@ -25,5 +25,6 @@ Submodules
    api/index
    plots/index
    utils/index
+   testing/index
    simpleapi
    fitfunctions

docs/source/api/python/mantid/testing/assert_almost_equal.rst

@@ -0,0 +1,19 @@
+.. _mantid.testing.assert_almost_equal:
+
+=====================
+ assert_almost_equal
+=====================
+
+This is a Python function for testing if two modules are within a tolerance
+
+
+.. module:`mantid.testing`
+
+.. automodule:: mantid.testing.assert_almost_equal
+    :members:
+    :undoc-members:
+    :inherited-members:
+
+See Also
+--------
+:ref:`algm-CompareWorkspaces`

docs/source/api/python/mantid/testing/index.rst

@@ -0,0 +1,13 @@
+.. _Mantid_testing:
+
+======================
+ :mod:`mantid.testing`
+======================
+
+.. module:: mantid.testing
+
+.. toctree::
+   :glob:
+   :maxdepth: 1
+
+   *

docs/source/release/v6.9.0/Framework/Python/New_features/36457.rst

@@ -0,0 +1 @@
+- New function :ref:`assert_almost_equal <mantid.testing.assert_almost_equal>` to make testing equality between workspaces more convenient.