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From: "ike " <ike.marsa@gmail.com>
Newsgroups: comp.soft-sys.matlab
Subject: Re: question about gradient function
Date: Wed, 2 May 2012 07:48:06 +0000 (UTC)
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"Matt J" wrote in message <jmk2uj$jsb$1@newscl01ah.mathworks.com>...
> "arron" wrote in message <jmi6n4$f6j$1@newscl01ah.mathworks.com>...
> > also when i try what you have said, i get:
> > 
> > subscript indices must be real positive integers or logicals. 
> ============
> 
> If you've set i and j to values that are not real positive integers, it makes sense that you would get an error when trying to subscript with them.

how can i get gradient direction from every pixel ?
so how can i select pixels randomly ?