Re: How do I replace this "for" loop?

[Tom Holroyd]

Robert A. Macy wrote:
> How do I replace these "for" loops?
>
> for i=1:rowsdata
>   for k=1:columnsdata
>     angleofdata(i,k)=angle(data(i,k));

octave:1> help angle
angle is a built-in mapper function

 -- Mapping Function:  angle (Z)
     See arg.

"Mapping" means you can pass the whole matrix to it.

        angleofdata = angle(data);

>       if (angleofdata(i,k)>3)
>         angleofdata(i,k)=angleofdata(i,k)-2*pi();
>       endif

Tests are similar.

        idx = find(angleofdata > 3);

gives you indices of elements that satisfy the condition, so

        angleofdata(idx) = angleofdata(idx) - 2 * pi;
--
Dr. Tom Holroyd
"A man of genius makes no mistakes. His errors are volitional and
are the portals of discovery." -- James Joyce



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