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Subject: Re: Binary matrix?
Date: Sun, 21 Oct 2012 15:12:07 +0000 (UTC)
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Each element is a single bit.  If I keep each element as uint8, I waste a lot of memory.  I was only suggesting I could possibly read the file in as a stream of uint8, but then I'd have to index it, i.e.  figure out which uint8 to use, then extract a particular bit from that uint8.  If I could directly index B(x,y) and get binary/boolean results without wasting memory, that would be better.

"Matt J" wrote in message <k5vuu0$5ua$1@newscl01ah.mathworks.com>...
> "Chuck37" wrote in message <k5vp68$h5o$1@newscl01ah.mathworks.com>...
> > I'm looking for suggestions on how to work with a 2D array of binary values.  I have the data in a file, but I'd like to have a 2D matrix of binaries that I can look up values in.  The matrix size is way too big to just let the binaries be wastefully stored as doubles.  I could read the file in as characters or uint8 or something, but then I'd need to figure out how to index into this.  Is there an easier way?
> ===========
> 
> I'm not sure what you think is more difficult about indexing a uint8 matrix than a double matrix. It's exactly the same.
> 
> BTW, once you've read in to a uint8 matrix, it would probably be appropriate to convert it to type logical. Also, be aware that sparse matrices can hold type logical, if that's applicable to you.