Re: Weirdness from double integrals?
- To: mathgroup at smc.vnet.net
- Subject: [mg95755] Re: Weirdness from double integrals?
- From: Erik Max Francis <max at alcyone.com>
- Date: Mon, 26 Jan 2009 05:02:56 -0500 (EST)
- References: <200901251153.GAA00724@smc.vnet.net> <glj8e1$doa$1@smc.vnet.net>
danl at wolfram.com wrote: > There are many subtleties to this. First, if you do an explicit multiple > integral (that is, using ont Integrate rather than iterating several of > them), then the GenerateConditions option is only used for the last > integration. This is documented but certainly constitutes "fine print". > For the GenerateConditions->False behavior of prior integrals, it is > common that they might give a spurious zero due to splitting ranges and > making conflicting hidden assumptions on parameters that cause results to > be not everywhere applicable. > > One possible way around might be to set GenerateConditions->True so that > it will be in effect for all levels of the integration. > > Integrate[integrand[[3]], {x, -x0, x0}, {y, -y0, y0}, > GenerateConditions -> True] > > Problem now is Mathematica 7 claims this diverges. I need to look into > this more closely, but offhand I have to say this looks like a bug in > convergence testing. Okay, so there _is_ something goofy going on here. > As you have found, best is to give applicable assumptions. This variant > gives a useful result. I've verified this works. Thanks. -- Erik Max Francis && max at alcyone.com && http://www.alcyone.com/max/ San Jose, CA, USA && 37 18 N 121 57 W && AIM, Y!M erikmaxfrancis Only love is worth the risk -- Oleta Adams
- References:
- Weirdness from double integrals?
- From: Erik Max Francis <max@alcyone.com>
- Weirdness from double integrals?