diff toolboxes/FullBNT-1.0.7/KPMstats/multinomial_sample.m @ 0:e9a9cd732c1e tip

first hg version after svn

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolboxes/FullBNT-1.0.7/KPMstats/multinomial_sample.m	Tue Feb 10 15:05:51 2015 +0000
@@ -0,0 +1,22 @@
+function Y = sample_cond_multinomial(X, M)
+% SAMPLE_MULTINOMIAL Sample Y(i) ~ M(X(i), :)
+% function Y = sample_multinomial(X, M)
+%
+% X(i) = i'th sample
+% M(i,j) = P(Y=j | X=i) = noisy channel model
+%
+% e.g., if X is a binary image,
+% Y = sample_multinomial(softeye(2, 0.9), X)
+% will create a noisy version of X, where bits are flipped with probability 0.1
+
+if any(X(:)==0)
+  error('data must only contain positive integers')
+end
+
+Y = zeros(size(X));
+for i=min(X(:)):max(X(:))
+  ndx = find(X==i);
+  Y(ndx) = sample_discrete(M(i,:), length(ndx), 1);
+end
+
+