Mercurial > hg > camir-aes2014
diff toolboxes/FullBNT-1.0.7/KPMtools/ind2subvKPM.m @ 0:e9a9cd732c1e tip
first hg version after svn
author | wolffd |
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date | Tue, 10 Feb 2015 15:05:51 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/toolboxes/FullBNT-1.0.7/KPMtools/ind2subvKPM.m Tue Feb 10 15:05:51 2015 +0000 @@ -0,0 +1,57 @@ +function sub = ind2subvKPM(siz, ndx) +% IND2SUBV Like the built-in ind2sub, but returns the answer as a row vector. +% sub = ind2subv(siz, ndx) +% +% siz and ndx can be row or column vectors. +% sub will be of size length(ndx) * length(siz). +% +% Example +% ind2subv([2 2 2], 1:8) returns +% [1 1 1 +% 2 1 1 +% ... +% 2 2 2] +% That is, the leftmost digit toggle fastest. +% +% See also SUBV2IND + +n = length(siz); + + +if n==0 + sub = ndx; + return; +end + +if all(siz==2) + sub = dec2bitv(ndx-1, n); + sub = sub(:,n:-1:1)+1; + return; +end + +cp = [1 cumprod(siz(:)')]; +ndx = ndx(:) - 1; +sub = zeros(length(ndx), n); +for i = n:-1:1 % i'th digit + sub(:,i) = floor(ndx/cp(i))+1; + ndx = rem(ndx,cp(i)); +end + + + +%%%%%%%%%% + +function bits = dec2bitv(d,n) +% DEC2BITV Convert a decimal integer to a bit vector. +% bits = dec2bitv(d,n) is just like the built-in dec2bin, except the answer is a vector, not a string. +% n is an optional minimum length on the bit vector. +% If d is a vector, each row of the output array will be a bit vector. + + +if (nargin<2) + n=1; % Need at least one digit even for 0. +end +d = d(:); + +[f,e]=log2(max(d)); % How many digits do we need to represent the numbers? +bits=rem(floor(d*pow2(1-max(n,e):0)),2);