Re: numerical integration

*To*: mathgroup at smc.vnet.net*Subject*: [mg110628] Re: numerical integration*From*: Peter Pein <petsie at dordos.net>*Date*: Tue, 29 Jun 2010 06:59:28 -0400 (EDT)*References*: <i09fgp$526$1@smc.vnet.net>

Am Mon, 28 Jun 2010 06:29:45 +0000 (UTC) schrieb ofer <ofershl at gmail.com>: > hi, > i have a pretty nasty double integral which i need to solve > numerically but mathematica gives me error messages when i try to > solve it straightforward using NIntegrate > > the integrand is: > > Exp[-I*\[Lambda]*(x+y)]*(x-y)*((Sinh[Pi*(x+I*\[Epsilon])]*Sinh[Pi*(y-I*\[Epsilon])])^-2 > -(Sinh[Pi*(x-I*\[Epsilon])]*Sinh[Pi*(y+I*\[Epsilon])])^-2) > > in the limits x=-infinity..infinity, y=-infinity..infinity > > with epsilon==>0 > > i'm new to mathematica and will appreciate any suggestions > Assuming you replaced epsilon and lambda by numerical values, I can not understand why NIntegrate fails. If you didn't so, you'll get an error stating that the integrand is nowhere numeric. ("The integrand" ... "has evaluated to non-numerical values for all sampling points in the region with boundaries"...) Peter