def test_morph(self):
"""check MorphStretch.morph()
"""
morph = MorphStretch()
# Stretch by 50%
morph.stretch = 0.5
xobj, yobj, xref, yref = morph(self.xobj, self.yobj, self.xref,
self.yref)
# Reference should be unchanged
self.assertTrue(numpy.allclose(self.yref, yref))
# Compare to new function. Note that due to interpolation, there will
# be issues at the boundary of the step function. This will distort up
# to two points in the interpolated function, and those points should
# be off by at most 0.5.
newstep = heaviside(xobj, 1.5, 3)
res = sum(numpy.fabs(newstep - yobj))
self.assertTrue(res < 1)
# Stretch by -10%
morph.stretch = -0.1
xobj, yobj, xref, yref = morph(self.xobj, self.yobj, self.xref,
self.yref)
# Reference should be unchanged
self.assertTrue(numpy.allclose(self.yref, yref))
# Compare to new function. Note that due to interpolation, there will
# be issues at the boundary of the step function. This will distort up
# to two points in the interpolated function, and those points should
# be off by at most 0.5.
newstep = heaviside(xobj, 0.9, 1.8)
res = sum(numpy.fabs(newstep - yobj))
self.assertTrue(res < 1)
return