From: "moth" <rancidmoth@yahoo.com>
Subject: Greens function
Date: Thu, 24 Aug 2000 11:24:05 +1000
Newsgroups: sci.math
Summary: [missing]

hello,

i am having some difficulty with a particular integral involving a greens
function.

my greens function has the form,

G =  K(u',v')* sum(q=1,q=inf) w(u',v')*H[q](u',v')*H[q](u,v)*F[q](r,r')

where K is just some function, H[q](u,v) (meaning H subscript q of coord u
and v) is an orthogonal function satisfying

integral( w(u,v)*H[q](u,v)*H[s](u,v)) = kronecker_delta(q,s)

where w(u,v) is the weight.

and F(r,r') is the "radial" part of the greens function.  the summation
involving the H functions reminds me of the deltafunction, so im guessing
that the integral involving,

sum(q=1,inf) ingetral ( K(u',v')*w(u',v')*H[q](u',v')*H[s](u',v'); du' dv' )

should drop out to something rather nice.  however since there is a F[q] in
the summation we dont exactly have a deltafunction, which means we have the
above integral that has a function multiplying or shifting the weight.  is
this a common type of integral? am i missing something obvious?

cheers
moth