testUtils.py

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"""Utilities that should be imported into the lsst.geom namespace when
lsst.geom is used
 
In the case of the assert functions, importing them makes them available in lsst.utils.tests.TestCase
"""
__all__ = []
 
import math
 
import numpy as np
 
import lsst.utils.tests
from ._geom import arcseconds
 
 
def extraMsg(msg):
    """Format extra error message, if any
    """
    if msg:
        return ": " + msg
    return ""
 
 
@lsst.utils.tests.inTestCase
def assertAnglesAlmostEqual(testCase, ang0, ang1, maxDiff=0.001*arcseconds,
                            ignoreWrap=True, msg="Angles differ"):
    r"""Assert that two `~lsst.geom.Angle`\ s are almost equal, ignoring
    wrap differences by default.
 
    If both arguments are NaN the assert will pass.  If one of the arguments
    is NaN but the other is not the assert will fail.
 
    Parameters
    ----------
    testCase : `unittest.TestCase`
        test case the test is part of; an object supporting one method:
        fail(self, msgStr)
    ang0 : `lsst.geom.Angle`
        angle 0
    ang1 : `lsst.geom.Angle`
        angle 1
    maxDiff : `lsst.geom.Angle`
        maximum difference between the two angles
    ignoreWrap : `bool`
        ignore wrap when comparing the angles?
 
        - if True then wrap is ignored, e.g. 0 and 360 degrees are considered
          equal
        - if False then wrap matters, e.g. 0 and 360 degrees are considered
          different
 
    msg : `str`
        exception message prefix; details of the error are appended after ": "
 
    Raises
    ------
    AssertionError
        Raised if the difference is greater than ``maxDiff``
    """
    isNan0 = math.isnan(ang0.asRadians())
    isNan1 = math.isnan(ang1.asRadians())
    if isNan0 and isNan1:
        return
    if isNan0:
        testCase.fail("ang0 is NaN")
    if isNan1:
        testCase.fail("ang1 is NaN")
    measDiff = ang1 - ang0
    if ignoreWrap:
        measDiff = measDiff.wrapCtr()
    if abs(measDiff) > maxDiff:
        testCase.fail("%s: measured difference %s arcsec > max allowed %s arcsec" %
                      (msg, measDiff.asArcseconds(), maxDiff.asArcseconds()))
 
 
@lsst.utils.tests.inTestCase
def assertPairsAlmostEqual(testCase, pair0, pair1, maxDiff=1e-7, msg="Pairs differ"):
    """Assert that two Cartesian points are almost equal.
 
    Each point can be any indexable pair of two floats, including
    Point2D or Extent2D, a list or a tuple.
 
    Parameters
    ----------
    testCase : `unittest.TestCase`
        test case the test is part of; an object supporting one method: fail(self, msgStr)
    pair0 : pair of `float`
        pair 0
    pair1 : pair of `floats`
        pair 1
    maxDiff : `float`
        maximum radial separation between the two points
    msg : `str`
        exception message prefix; details of the error are appended after ": "
 
    Raises
    ------
    AssertionError
        Raised if the radial difference is greater than ``maxDiff``
 
    Notes
    -----
    .. warning::
 
       Does not compare types, just compares values.
    """
    if len(pair0) != 2:
        raise RuntimeError("len(pair0)=%s != 2" % (len(pair0),))
    if len(pair1) != 2:
        raise RuntimeError("len(pair1)=%s != 2" % (len(pair1),))
 
    pairDiff = [float(pair1[i] - pair0[i]) for i in range(2)]
    measDiff = math.hypot(*pairDiff)
    if measDiff > maxDiff:
        testCase.fail("%s: measured radial distance = %s > maxDiff = %s, pair0=(%r, %r), pair1=(%r, %r)" %
                      (msg, measDiff, maxDiff, pair0[0], pair0[1], pair1[0], pair1[1]))
 
 
@lsst.utils.tests.inTestCase
def assertPairListsAlmostEqual(testCase, list0, list1, maxDiff=1e-7, msg=None):
    """Assert that two lists of Cartesian points are almost equal
 
    Each point can be any indexable pair of two floats, including
    Point2D or Extent2D, a list or a tuple.
 
    Parameters
    ----------
    testCase : `unittest.TestCase`
        test case the test is part of; an object supporting one method: fail(self, msgStr)
    list0 : `list` of pairs of `float`
        list of pairs 0
    list1 : `list` of pairs of `float`
        list of pairs 1
    maxDiff : `float`
        maximum radial separation between the two points
    msg : `str`
        additional information for the error message; appended after ": "
 
    Raises
    ------
    AssertionError
        Raised if the radial difference is greater than ``maxDiff``
 
    Notes
    -----
    .. warning::
 
       Does not compare types, just values.
    """
    testCase.assertEqual(len(list0), len(list1))
    lenList1 = np.array([len(val) for val in list0])
    lenList2 = np.array([len(val) for val in list1])
    testCase.assertTrue(np.all(lenList1 == 2))
    testCase.assertTrue(np.all(lenList2 == 2))
 
    diffArr = np.array([(val0[0] - val1[0], val0[1] - val1[1])
                        for val0, val1 in zip(list0, list1)], dtype=float)
    sepArr = np.hypot(diffArr[:, 0], diffArr[:, 1])
    badArr = sepArr > maxDiff
    if np.any(badArr):
        maxInd = np.argmax(sepArr)
        testCase.fail("PairLists differ in %s places; max separation is at %s: %s > %s%s" %
                      (np.sum(badArr), maxInd, sepArr[maxInd], maxDiff, extraMsg(msg)))
 
 
@lsst.utils.tests.inTestCase
def assertSpherePointsAlmostEqual(testCase, sp0, sp1, maxSep=0.001*arcseconds, msg=""):
    r"""Assert that two `~lsst.geom.SpherePoint`\ s are almost equal
 
    Parameters
    ----------
    testCase : `unittest.TestCase`
        test case the test is part of; an object supporting one method:
        fail(self, msgStr)
    sp0 : `lsst.geom.SpherePoint`
        SpherePoint 0
    sp1 : `lsst.geom.SpherePoint`
        SpherePoint 1
    maxSep : `lsst.geom.Angle`
        maximum separation
    msg : `str`
        extra information to be printed with any error message
 
    Raises
    ------
    AssertionError
        The SpherePoints are not equal.
    """
    if sp0.separation(sp1) > maxSep:
        testCase.fail("Angular separation between %s and %s = %s\" > maxSep = %s\"%s" %
                      (sp0, sp1, sp0.separation(sp1).asArcseconds(), maxSep.asArcseconds(), extraMsg(msg)))
 
 
@lsst.utils.tests.inTestCase
def assertSpherePointListsAlmostEqual(testCase, splist0, splist1, maxSep=0.001*arcseconds, msg=None):
    r"""Assert that two lists of `~lsst.geom.SpherePoint`\ s are almost equal
 
    Parameters
    ----------
    testCase : `unittest.TestCase`
        test case the test is part of; an object supporting one method:
        fail(self, msgStr)
    splist0 : `list` of `lsst.geom.SpherePoint`
        list of SpherePoints 0
    splist1 : `list` of `lsst.geom.SpherePoint`
        list of SpherePoints 1
    maxSep : `lsst.geom.Angle`
        maximum separation
    msg : `str`
        exception message prefix; details of the error are appended after ": "
 
    Raises
    ------
    AssertionError
        The SpherePoint lists are not equal.
    """
    testCase.assertEqual(len(splist0), len(splist1), msg=msg)
    sepArr = np.array([sp0.separation(sp1)
                       for sp0, sp1 in zip(splist0, splist1)])
    badArr = sepArr > maxSep
    if np.any(badArr):
        maxInd = np.argmax(sepArr)
        testCase.fail("SpherePointLists differ in %s places; max separation is at %s: %s\" > %s\"%s" %
                      (np.sum(badArr), maxInd, sepArr[maxInd].asArcseconds(),
                       maxSep.asArcseconds(), extraMsg(msg)))
 
 
@lsst.utils.tests.inTestCase
def assertBoxesAlmostEqual(testCase, box0, box1, maxDiff=1e-7, msg="Boxes differ"):
    """Assert that two boxes (`~lsst.geom.Box2D` or `~lsst.geom.Box2I`) are
    almost equal
 
    Parameters
    ----------
    testCase : `unittest.TestCase`
        test case the test is part of; an object supporting one method:
        fail(self, msgStr)
    box0 : `lsst.geom.Box2D` or `lsst.geom.Box2I`
        box 0
    box1 : `lsst.geom.Box2D` or `lsst.geom.Box2I`
        box 1
    maxDiff : `float`
        maximum radial separation between the min points and max points
    msg : `str`
        exception message prefix; details of the error are appended after ": "
 
    Raises
    ------
    AssertionError
        Raised if the radial difference of the min points or max points is
        greater than maxDiff
 
    Notes
    -----
    .. warning::
 
       Does not compare types, just compares values.
    """
    assertPairsAlmostEqual(testCase, box0.getMin(),
                           box1.getMin(), maxDiff=maxDiff, msg=msg + ": min")
    assertPairsAlmostEqual(testCase, box0.getMax(),
                           box1.getMax(), maxDiff=maxDiff, msg=msg + ": max")