Path: news.mathworks.com!not-for-mail From: <HIDDEN> Newsgroups: comp.soft-sys.matlab Subject: Re: Binary matrix? Date: Sun, 21 Oct 2012 15:12:07 +0000 (UTC) Organization: Rincon Research Corp Lines: 10 Message-ID: <k613c7$3kt$1@newscl01ah.mathworks.com> References: <k5vp68$h5o$1@newscl01ah.mathworks.com> <k5vuu0$5ua$1@newscl01ah.mathworks.com> Reply-To: <HIDDEN> NNTP-Posting-Host: www-04-blr.mathworks.com Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Trace: newscl01ah.mathworks.com 1350832327 3741 172.30.248.35 (21 Oct 2012 15:12:07 GMT) X-Complaints-To: news@mathworks.com NNTP-Posting-Date: Sun, 21 Oct 2012 15:12:07 +0000 (UTC) X-Newsreader: MATLAB Central Newsreader 2235717 Xref: news.mathworks.com comp.soft-sys.matlab:781098 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.