Finding the other elements in array or matrices

[Marc Normandin]

pauljoseph wrote:
> Hi,
> Can someone help me on how to do this effectively in Octave?
> 
> for example I have an array:
> a=[10,20,30,40,50];
> 
> and I have another list
> mask=[1,4];
> 
> if I type
> a(mask)
> 
> , I will get:
> 10, 40
> 
> But what I want to get is the other elements which is 2,3, and 5, which
> gives
> 20,30,50
> 
> And what I have in hand is only a and mask.
> 
> I would appreciate your help :)
> --
> View this message in context: http://www.nabble.com/Finding-the-other-elements-in-array-or-matrices-tp14859516p14859516.html
> Sent from the Octave - General mailing list archive at Nabble.com.

There's likely to be a more efficient way to handle this problem, but
here's one possible solution.

mask2=1:length(a);
mask2(mask)=0;
idx=find(mask2);
a(idx)

The same idea can be extended to matrices, however its implementation
will depend upon how the mask is defined.

Regards,
Marc