Mercurial > hg > smallbox
view util/sparco utils/genSampling.m @ 209:dfa795944aae luisf_dev
fixed some bugs in the default parameters of SMALL_two_step_DL
author | bmailhe |
---|---|
date | Wed, 21 Mar 2012 16:21:18 +0000 |
parents | 62f20b91d870 |
children |
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function [minIntrVec,stat,actpctg] = genSampling(pdf,iter,tol) %[mask,stat,N] = genSampling(pdf,iter,tol) % % a monte-carlo algorithm to generate a sampling pattern with % minimum peak interference. The number of samples will be % sum(pdf) +- tol % % pdf - probability density function to choose samples from % iter - number of tries % tol - the deviation from the desired number of samples in samples % % returns: % mask - sampling pattern % stat - vector of min interferences measured each try % actpctg - actual undersampling factor % % (c) Michael Lustig 2007 % This file is used with the kind permission of Michael Lustig % (mlustig@stanford.edu), and originally appeared in the % SparseMRI toolbox, http://www.stanford.edu/~mlustig/ . % % $Id: genSampling.m 1040 2008-06-26 20:29:02Z ewout78 $ % h = waitbar(0); pdf(find(pdf>1)) = 1; K = sum(pdf(:)); minIntr = 1e99; minIntrVec = zeros(size(pdf)); for n=1:iter tmp = zeros(size(pdf)); while abs(sum(tmp(:)) - K) > tol tmp = rand(size(pdf))<pdf; end TMP = ifft2(tmp./pdf); if max(abs(TMP(2:end))) < minIntr minIntr = max(abs(TMP(2:end))); minIntrVec = tmp; end stat(n) = max(abs(TMP(2:end))); % waitbar(n/iter,h); end actpctg = sum(minIntrVec(:))/prod(size(minIntrVec)); % close(h);