Re: [Maxima-discuss] Bug in Integrate

[Barton W. <wi...@un...>]

This is a bug--if you could report it to our bug tracker , that would be great (http://sourceforge.net/p/maxima/bugs/)

A workaround seems to be to declare m to be a positive integer:

(%i1) (declare(m,integer), assume(m>0))$
(%i2) integrate(exp( -x^2/2 ) / sqrt(2*%pi) * x^m, x, -1/4, 1/4)$
(%i3) %,m = 4;
(%o3) (3*sqrt(2)*sqrt(%pi)-2^(5/2)*gamma_incomplete(5/2,1/32))/(sqrt(2)*sqrt(%pi))
(%i4) float(%);
(%o4) 1.5240024317779744*10^-4

This workaround should not be needed. Setting domain to complex makes answer to be wrong again :(


________________________________________
From: Sean Lake <ody...@gm...>
Sent: Sunday, April 27, 2014 19:37
To: max...@li...
Subject: [Maxima-discuss] Bug in Integrate

Hello All,

I'm not sure what the problem is, but I have a simple test case. Here's the code:

integrate( exp( -x^2/2 ) / sqrt(2*%pi) * x^m, x, -0.25, 0.25 );
%, m = 4;

The result comes out negative, and it should be positive. Maxima produces the correct result if the value of m is inserted before doing the integral.

Thanks,
Sean

Maxima 5.33.0 http://maxima.sourceforge.net
using Lisp SBCL 1.1.17
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