       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

• Prev by Date: Re: how to automatically include own package into different
• Next by Date: hearing a plot
• Previous by thread: numerical integration
• Next by thread: Re: numerical integration