def cell_orientation(self, restriction):
"""Cell orientation as a GEM expression."""
f = {None: 0, '+': 0, '-': 1}[restriction]
# Assume self._cell_orientations tuple is set up at this point.
co_int = self._cell_orientations[f]
return gem.Conditional(
gem.Comparison("==", co_int, gem.Literal(1)), gem.Literal(-1),
gem.Conditional(gem.Comparison("==", co_int, gem.Zero()),
gem.Literal(1), gem.Literal(numpy.nan)))
def conditional(self, o, condition, then, else_):
assert condition.shape == ()
shape, = set([then.shape, else_.shape])
indices = gem.indices(len(shape))
return gem.ComponentTensor(
gem.Conditional(condition, gem.Indexed(then, indices),
gem.Indexed(else_, indices)), indices)