comparison toolboxes/FullBNT-1.0.7/KPMtools/logsum.m @ 0:e9a9cd732c1e tip

first hg version after svn

+function y=logsum(x,d)
+%LOGSUM logsum(x,d)=log(sum(exp(x),d))
+%  d gives dimension to sum along
+
+%      Copyright (C) Mike Brookes 1998
+%
+%      Last modified Mon Oct 12 15:47:25 1998
+%
+%   VOICEBOX is a MATLAB toolbox for speech processing. Home page is at
+%   http://www.ee.ic.ac.uk/hp/staff/dmb/voicebox/voicebox.html
+%
+
+if nargin==1
+   d=[find(size(x)-1) 1];
+   d=d(1);
+end
+n=size(x,d);
+if n<=1, y=x; return; end
+s=size(x);
+p=[d:ndims(x) 1:d-1];
+z=reshape(permute(x,p),n,prod(s)/n);
+
+y=max(z);
+y=y+log(sum(exp(z-y(ones(n,1),:))));
+
+s(d)=1;
+y=ipermute(reshape(y,s(p)),p);
+