From: <HIDDEN>
Newsgroups: comp.soft-sys.matlab
Subject: Re: What a hell is wrong with logical indexing??? Really???
Date: Thu, 6 May 2010 14:48:04 +0000 (UTC)
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Nothing seems out of sorts to me.  In the first case you are assigning a double to a double.  In the second case you are assigning a double to a logical, so MATLAB preserves the logical.  Sort of like this:

A = 3;
A(2) = uint8(9);
A(3) = 'r';
whos A

Now as for the warning in your case, yet none in the above example, I question that.