% Draw a single mode of circular vibrating membrane

format compact;
A = 10;				% radius

NptsR=51;
NptsT=51;

r=linspace(0,A,NptsR);
t=linspace(0,2*pi,NptsT);
[R,T]=meshgrid(r,t);
X=R.*cos(T);
Y=R.*sin(T);

fs=8;
clf

M = 0; N = 3;

zmn=besselzero(M,N,1);
lambda=(zmn(N)/A)^2;
B=besselj(M,sqrt(lambda)*R).*cos(M*T);
surf(X,Y,B)
shading interp; colormap jet;
axis tight;
drawnow
  
%print -dpng bess_MN.png	
%print -depsc bess_MN.eps

