MATLAB black hole variable

Does MATLAB have a "blackhole" or discard variable?

Say I'm doing something like:

[ rows cols ] = size( A ) ;

But I don't want rows to be stored. Is there a "black hole" variable where I can send values to die?

So the assign开发者_开发技巧ment would be like

[ BLACKHOLE, cols ] = size( A ) ;

Where BLACKHOLE means throw the value away and don't create a variable for it.

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For 2009b or later, there is the tilde sign "~"

[~,cols] = size(A);

Alternatively, in your specific case

cols = size(A,2);

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For compatibility with Matlab versions prior to 2009b you can use the following technique

[cols, cols] = size(A);

See http://blogs.mathworks.com/steve/2010/01/11/about-the-unused-argument-syntax-in-r2009b/ for example