Hi everyone,
Doing some calculations I noticed that there is something wrong with
imlementation of abs() and cabs(). Basically, in the code below I can
calculate and plot sqrt(re^2 + im^2), but I cannot do it with abs(),
nor with cabs(): it never finishes and Maxima does not react to the
keyboard interrupt either. Maybe, this triggers a bug in gcl?
I run this version of maxima (on Debian sid):
Maxima 5.20.1 http://maxima.sourceforge.net
using Lisp GNU Common Lisp (GCL) GCL 2.6.7 (a.k.a. GCL)
========================================================
eps : [1,2];
mu : [1,1];
n : sqrt(eps*mu);
vc : [0,0.5];
epst : eps*(1-vc^2)/(1-n^2*vc^2);
mut : mu*(1-vc^2)/(1-n^2*vc^2);
a : vc*(n^2-1)/(1-n^2*vc^2);
kxe : -%i*sqrt(-k0^2*eps*mut+eps/epst*(kz+k0*a)^2+ky^2);
kxh : -%i*sqrt(-k0^2*mu*epst+mu/mut*(kz+k0*a)^2+ky^2);
betae : k0*kxe*epst/(k0^2*epst*mut-(kz+k0*a)^2);
betah : k0*kxh*mut/(k0^2*epst*mut-(kz+k0*a)^2);
alpha : -ky*(kz+k0*a)/(k0^2*epst*mut-(kz+k0*a)^2);
a1 : part(alpha,1); a2 : part(alpha,2);
be1 : part(betae,1); be2 : part(betae,2);
bh1 : part(betah,1); bh2 : part(betah,2);
denom : (a1-a2)^2+(be1+be2)*(bh1+bh2);
Ree : -((a1-a2)^2-(be1-be2)*(bh1+bh2))/denom;
plot3d(sqrt(realpart(subst(k0=%i,Ree))^2+imagpart(subst(k0=%i,Ree))^2),[ky,-3,3],[kz,-3,3]);
plot3d(cabs(subst(k0=%i,Ree)),[ky,-3,3],[kz,-3,3]);
plot3d(abs(subst(k0=%i,Ree)),[ky,-3,3],[kz,-3,3]);
--
Stanislav