def getCext(particle, alpha, b, nmax):
sum = 0
k = particle.k
for l in range(1, nmax+1):
c = particle.c1
cv = spheroidal.get_cv(1, l, c, particle.type)
sum += power(1j, -l) * b[l-1] *\
spheroidal.ang1_cv(1, l, c, cv, particle.type, cos([alpha]))[0]
return 4 * pi / (k * k) * real(sum)
def getB(self, particle, c, l):
cv = spheroidal.get_cv(1, l, c, particle.type)
return 2 * pow(1j, l) * spheroidal.ang1_cv(1, l, c, cv, particle.type, cos([self.alpha]))[0]
