%<title> MATLAB for FYS208 </title>
%<plaintext>
%% Plotting the 3-dim FYS208
%% Brillouin, 2dim crystal, tight binding
%  can be run by Matlab< fff.html
T41=41;
T20=20;
for i=1:T41
   x(i)=-pi+ pi/T20*(i-1);
end
for i=1:T41
   y(i)=-pi+ pi/T20*(i-1);
end
 for i=1:T41
    for j=1:T41
      f(i,j)=3.0-cos(x(i))-cos(y(j));
    end
   end
 u(:)=3.0-cos(x(:));
%% Mesh surface:
   surfl(f)
%% Add shading
  shading interp
  colormap(gray);
%% Plot in grey and add contours.... This is good !
 surfc(f)
 shading interp
%% Postscript
  print -deps Plot1.eps
%% Aspect Ratio  (get current ...  gca )
  set(gca,'AspectRatio',[1 1])
  print -deps Plot2.eps
%%  contour 
  contour(f,12)
  set(gca,'AspectRatio',[1 1])
   print -deps Plot2.eps
%% contour with labels 
  c= contour(f,12);
  clabel(c);