def test_differentiator_flags_for_nonsmooth_and_discontinuous():
import pymbolic.functions as pf
from pymbolic.mapper.differentiator import differentiate
x = prim.Variable("x")
with pytest.raises(ValueError):
differentiate(pf.fabs(x), x)
result = differentiate(pf.fabs(x), x, allowed_nonsmoothness="continuous")
assert result == pf.sign(x)
with pytest.raises(ValueError):
differentiate(pf.sign(x), x)
result = differentiate(pf.sign(x), x, allowed_nonsmoothness="discontinuous")
assert result == 0
def map_math_functions_by_name(i, func, pars, allowed_nonsmoothness="none"):
def make_f(name):
return primitives.Lookup(primitives.Variable("math"), name)
if func == make_f("sin") and len(pars) == 1:
return make_f("cos")(*pars)
elif func == make_f("cos") and len(pars) == 1:
return -make_f("sin")(*pars)
elif func == make_f("tan") and len(pars) == 1:
return make_f("tan")(*pars)**2 + 1
elif func == make_f("log") and len(pars) == 1:
return primitives.quotient(1, pars[0])
elif func == make_f("exp") and len(pars) == 1:
return make_f("exp")(*pars)
elif func == make_f("sinh") and len(pars) == 1:
return make_f("cosh")(*pars)
elif func == make_f("cosh") and len(pars) == 1:
return make_f("sinh")(*pars)
elif func == make_f("tanh") and len(pars) == 1:
return 1 - make_f("tanh")(*pars)**2
elif func == make_f("expm1") and len(pars) == 1:
return make_f("exp")(*pars)
elif func == make_f("fabs") and len(pars) == 1:
if allowed_nonsmoothness in ["continuous", "discontinuous"]:
from pymbolic.functions import sign
return sign(*pars)
else:
raise ValueError("fabs is not smooth"
", pass allowed_nonsmoothness='continuous' "
"to return sign")
elif func == make_f("copysign") and len(pars) == 2:
if allowed_nonsmoothness == "discontinuous":
return 0
else:
raise ValueError("sign is discontinuous"
", pass allowed_nonsmoothness='discontinuous' "
"to return 0")
else:
raise RuntimeError("unrecognized function, cannot differentiate")