Re: Function of vector with meshgrid and surf

[karl]

Am 12.11.2015 um 00:26 schrieb Sebastian Schöps:
> karl wrote
> > I have a small problem with the syntax.
> > ...
> > How do I have to modify the line "Z=frame([X,Y])" that the surf command
> > works and gives the surface?
> X and Y are matrices (in your case 11x11) and [X,Y] is even 11x(2*11). Your
> functions expects vectors and thus it does not work properly. You either
> have to modify "frame" to allow matrix input or you have to loop over the
> entries. Here are three possibilities:
>
> function karl
>         x1=0:0.1:1;
>         [X,Y]=meshgrid(x1,x1);
>
>         Z=frame_modified(X,Y);
>         figure;
>         surf(X,Y,Z);
>         
>         for i=1:size(Z,1)
>                 Z(i,:)=frame([X(i,:); Y(i,:)]);
>         end
>         figure;
>         surf(X,Y,Z);
>
>         for i=1:size(Z,1)
>                 for j=1:size(Z,1)
>                         Z(i,j)=frame([X(i,j); Y(i,j)]);
>                 end
>         end
>         figure;
>         surf(X,Y,Z);
>         
> end
>
> function fr = frame_modified (x,y)
>         fr=x+y;
> endfunction
>
> function fr = frame (x)
> fr=x(1,:)+x(2,:);
> endfunction
>
>
>
> --
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> http://octave.1599824.n4.nabble.com/Function-of-vector-with-meshgrid-and-surf-tp4673436p4673444.html
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>
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Hallo Sebastian thanks for the answer, BUT:
I can't modify frame as I wrote already, since then I have to change many other 
things, and I would like
to avoid looping. Let us consider a simpler case:

function fr = frame1 (x)
fr=x(1)+x(2);
endfunction

Is it possible in this case, i.e. with no modification of frame1, to avoid 
looping?

Ciao
Karl