def bessel_k(self, o, nup, fp):
nu, f = o.ufl_operands
if not (nup is None or isinstance(nup, Zero)):
error("Differentiation of bessel function w.r.t. nu is not supported.")
if isinstance(nu, Zero):
op = -bessel_K(1, f)
else:
op = -0.5 * (bessel_K(nu-1, f) + bessel_K(nu+1, f))
return op * fp
def bessel_k(self, o, nup, fp):
nu, f = o.ufl_operands
if not (nup is None or isinstance(nup, Zero)):
error("Differentiation of bessel function w.r.t. nu is not supported.")
if isinstance(nu, Zero):
op = -bessel_K(1, f)
else:
op = -0.5 * (bessel_K(nu - 1, f) + bessel_K(nu + 1, f))
return op * fp
def bessel_k(self, o, nu, x):
nu, dummy = nu
if not (dummy is None or isinstance(dummy, Zero)):
error("Differentiation of bessel function w.r.t. nu is not supported.")
f, fp = x
o = self.reuse_if_possible(o, nu, f)
if nu == 0:
op = -bessel_K(1, f)
else:
op = -0.5 * (bessel_K(nu-1, f) + bessel_K(nu+1, f))
return (o, op*fp)
def bessel_k(self, o, nu, x):
nu, dummy = nu
if not (dummy is None or isinstance(dummy, Zero)):
error(
"Differentiation of bessel function w.r.t. nu is not supported."
)
f, fp = x
o = self.reuse_if_possible(o, nu, f)
if nu == 0:
op = -bessel_K(1, f)
else:
op = -0.5 * (bessel_K(nu - 1, f) + bessel_K(nu + 1, f))
return (o, op * fp)