On Dec 5, 2007, Daniel Lakeland wrote
>>
If I want to numerically calculate integrate(f(x),x,minf,inf) in
quadpack, I have to say
quad_qagi(f(x),x,minf,both)
which is so unintuitive that even after reading the docs several times
I spent about half an hour figuring it out. Worse yet, if I say
quad_qagi(f(x),x,minf,inf) I get half the integral that I expect (it
integrates -inf to 0)
>>
On Dec 5, 2007, Raymond Toy wrote:
>>
You are right. It is confusing. The maxima interface is a very thin
layer over the actual qagi function. That's my excuse, anyway. :-)
The interface should be changed to recognize recognize a to inf, minf to
a, and minf to inf. It should give errors for other cases.
I'll look into doing this.
>>
I can't get minf to work with quad_qagi
in any of the various permutations
(%i1) display2d:false$
(%i2) quad_qagi(exp(-x^2),x,0,inf);
(%o2) [0.88622692545276,7.101318390915455E-9,135,0]
(%i3) quad_qagi(exp(-x^2),x,minf,0);
(%o3) quad_qagi(%e^-x^2,x,minf,0,epsrel = 1.0E-8,epsabs = 0.0,limit = 200)
(%i4) quad_qagi(exp(-x^2),x,minf,inf);
(%o4) quad_qagi(%e^-x^2,x,minf,inf,epsrel = 1.0E-8,epsabs = 0.0,limit = 200)
(%i5) quad_qagi(exp(-x^2),x,minf,both);
(%o5) quad_qagi(%e^-x^2,x,minf,both,epsrel = 1.0E-8,epsabs = 0.0,limit =
200)
Ted Woollett