Hello all,
I'm trying to plot a numerical integral over a range of parameters to see how it behaves, and I'm running into problems using quad_qagi to do it. The code I want to run looks like:
f(x,y) := exp( - ( y - x - log( 1 +exp(y))/3)^2 / 2);
N(x) := quad_qagi( f(x, y), y, minf, inf )[1];
plot2d( N(x), [x, -5, 5] );
When I try to evaluate N(0.0), I get what looks like an unevaluated noun form (you'll need a fixed width font for this to make sense):
(%i27) quad_qagi( exp(-(y-log(exp(y) + 1)/3)^2/2), y, minf, inf );
y
log(%e + 1) 2
(y - ------------)
3
- -------------------
2
(%o27) quad_qagi(%e , y, minf, inf, epsrel = 1.e-8,
epsabs = 0.0, limit = 200)
ev(%, nouns); does nothing, though.
I don't really have a strong enough grasp of lisp to see why the quad_qagi function isn't doing what I expect, and would appreciate any help in this matter.
Thanks,
Sean