Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!umich!samsung!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!pacific.mps.ohio-state.edu!sun
From: sun@pacific.mps.ohio-state.edu (Mingqiu Sun)
Newsgroups: comp.lang.fortran
Subject: oscillatory integral: help needed
Message-ID: <1395@pacific.mps.ohio-state.edu>
Date: 11 Feb 90 03:17:14 GMT
Reply-To: sun@pacific.mps.ohio-state.edu (Mingqiu Sun)
Organization: Ohio State University, Physics Department
Lines: 10

Does anyone have any good routines/ideas of integrating oscillatory
functions of the form f(x)cos(a*x+b*x*X)?  integration intervals
can be something like [x1, x2] or [x1, +infinity].

One simple scheme is to transform ax+bxx to a new variable, say u.
then use routines that can evaluate f(u)cos(u). but unfortunately
this will introduce a divergent fact into the integrand which
makes the scheme inefficient and lack of precision.

All response will be appreciated.