Path: news.mathworks.com!not-for-mail From: "Colin " <colinzhe@gmail.com> Newsgroups: comp.soft-sys.matlab Subject: Re: Check if two shifted matrices are equal Date: Thu, 6 Nov 2008 21:12:01 +0000 (UTC) Organization: Harris Corporation Inc Lines: 32 Message-ID: <gevmj1$sq0$1@fred.mathworks.com> References: <gevia6$2hk$1@fred.mathworks.com> <vVIQk.3167$dy1.2828@newsfe01.iad> Reply-To: "Colin " <colinzhe@gmail.com> NNTP-Posting-Host: webapp-02-blr.mathworks.com Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 8bit X-Trace: fred.mathworks.com 1226005921 29504 172.30.248.37 (6 Nov 2008 21:12:01 GMT) X-Complaints-To: news@mathworks.com NNTP-Posting-Date: Thu, 6 Nov 2008 21:12:01 +0000 (UTC) X-Newsreader: MATLAB Central Newsreader 1567289 Xref: news.mathworks.com comp.soft-sys.matlab:499380 Walter Roberson <roberson@hushmail.com> wrote in message <vVIQk.3167$dy1.2828@newsfe01.iad>... > Colin wrote: > > > I have two matrices that are 1 x 130943 and contain hex values. > > > I want to be able to verify that they are in fact identical matrices but only one is shifted > > with respect to the other. > > Do you only need to know that they -are- identical (but perhaps shifted), or do you need to > know the amount of the shift? > > And do you happen to have any constraint on how much shift there would be? For example, > would it just happen to be the case that the shift would be by an even number of positions? > > Is there exactly 1 hex digit per array location? > > Would a fast "Not the same" or "Might be the same" be useful to you? e.g., are the > arrays often different and being the same is the much less common case that you can > afford to take longer to prove? For example, when two arrays are different, then > their histograms would often be different, so if the histograms are different then > you know [relatively quickly] that the arrays are not shifts of each other, and if > the histograms are the same then you could run a more detailed test. > > -- > .signature note: I am now avoiding replying to unclear or ambiguous postings. > Please review questions before posting them. Be specific. Use examples of what you mean, > of what you don't mean. Specify boundary conditions, and data classes and value > relationships -- what if we scrambled your data or used -Inf, NaN, or complex(rand,rand)? Sorry and to address your other questions, the matrix could be shifted by any arbitrary integer number up to the size of the matrix minus 1. There is a hex value at exactly every index.