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Topic: Best way to "classify" a vector? ("averaging" subsampling)
Replies: 4   Last Post: Mar 5, 2013 6:05 AM

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Luca

Posts: 77
Registered: 6/6/12
Re: Best way to "classify" a vector? ("averaging" subsampling)
Posted: Mar 5, 2013 6:05 AM
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TideMan <mulgor@gmail.com> wrote in message <348a0afd-3e60-4417-864d-
> So, you're doing the equivalent of taking daily means (if the t were Matlab days).
> Why is that dumb?


Don't know why it's dumb, it's just that it doesn't seem to be the best way. I would think there are some built-in matlab functions that I ignore.
More ore less it's taking daily means. But it's an operation also extremely common in imaging situations.
Suppose I want to simulate a digital camera with resolution 1000x1000. How would I do that? I compute with an higher resolution (say 4'000x4'000) what arrives on the detector, some kind of noise and distorsions etc... And then to go down to the actual resolution I do not subsample my original vector (1:4:4000), I average everything that has fallen within each pixel!
And this "integral subsampling" (if it's the correct name) it's what happens in a lot of the more diverse situations. (i.e. sensors measuring radioactivity counts dinamically etc...)


> The only thing I'd criticise about your method is the use of i as an index. By default i and j are sqrt(-1). This may seem trivial, but one day this will jump up and bite you. Use something else, like it or jt, for the index.

I think that would be too much for me!



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