Re: 3.4: one surface is missing (was: still problems, version?)

[Liam Groener]

On Jul 20, 2011, at 7:57 AM, Uwe Brauer wrote:

Regarding Re: still problems, version? (was: matlab code: isovalues and isosurface); Martin Helm <address@hidden> adds:

Hello

I finally installed the new octave3.4 on my Ubuntu machine.
Now the code runs without errors and the graphic I obtain is
"almost identically" to the one you and Liam obtained. There
is a difference: while in your case, there are 3 surfaces
(as they should be) in my case I only get the lower and
upper and the middle one is missing.

I run it twice once with daspect once without
despect. Dapsect only scales the surfaces differently.

The code in question is this one:

Here is the code which works for me

-------------------------------

graphics_toolkit fltk

function Psi=FdOn320(x,y,z)

r=sqrt(x.^2+y.^2+z.^2);

Psi=exp(-r./3).*(3*z.^2-r.^2).*2*sqrt(15/(120*pi))/81;

end

[x,y,z]=meshgrid(-20:.5:20);

Psi=FdOn320(x,y,z);

m=min(Psi(:));

M=max(Psi(:));

color=[1 1 0;1 0 1; 0 1 1;0 1 0;1 0 0; 0 0 1; 0 0 0];

n=5;

for i=1:n-1

   isovalue=m+i*(M-m)/n;

   fv = isosurface(x,y,z,Psi,isovalue);

   hpatch = patch(fv);

   isonormals(x,y,z,Psi,hpatch);

   Alphalevel=0.2+0.8*i/n;

% set(hpatch,'FaceAlpha',Alphalevel,'FaceColor',color(i,:),'EdgeColor','none')

    set(hpatch,'FaceColor',color(i,:),'EdgeColor','black')

%     daspect([1,1,1])

    view(3);

    axis tight

%     camlight left;

end

-----------------------------------

I attach the surface without daspect:

I am very puzzled, most like something is wrong in my
installation?

Uwe Brauer

<mysurface-nodaspect.jpg>

That is puzzling indeed. What do you get when you plot each level separately with something like:

[x,y,z]=meshgrid(-20:.5:20);

function Psi=FdOn320(x,y,z)

 r=sqrt(x.^2+y.^2+z.^2);

 Psi=exp(-r./3).*(3*z.^2-r.^2).*2*sqrt(15/(120*pi))/81;

endfunction 

 Psi=FdOn320(x,y,z);

 m=min(Psi(:));

 M=max(Psi(:));

 color=[1 1 0;1 0 1; 0 1 1;0 1 0;1 0 0; 0 0 1; 0 0 0];

 n=5;

 for i=1:n-1

     isovalue=m+i*(M-m)/n;

     fv = isosurface(x,y,z,Psi,isovalue);

     subplot(2,2,i)

     hpatch = patch(fv);

     isonormals(x,y,z,Psi,hpatch);

#     Alphalevel=0.2+0.8*i/n;

#      set(hpatch,'FaceAlpha',Alphalevel,'FaceColor','interp','EdgeColor','none')

       set(hpatch,'FaceColor',color(i,:),'EdgeColor','black')

       title(strcat('orbital-', num2str(n-i)))

#      set(hpatch,'FaceLighting','phong')

#      light ("Position", [1 1 5]);

      daspect([1,1,1])

      view(3); 

      axis tight

 %     camlight left; 

 end

I get: