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authorziejd22018-03-14 23:23:33 -0500
committerGitHub2018-03-14 23:23:33 -0500
commit1ff6baa44e22b91eefb48aea6f3befa078c0489b (patch)
treee0fd79d2e32fd2aedda2eadaed0f19af3514c520 /sourcecodes/bnt-master/KPMstats/multipdf.m
parent6882395afdadf4e982b25b5215071a0932730950 (diff)
parentc80226899f5cdd9f11c163817d59445213f5bef0 (diff)
downloadBNW-1ff6baa44e22b91eefb48aea6f3befa078c0489b.tar.gz
Merge pull request #1 from ziejd2/octave_php_separate
Octave php separate
Diffstat (limited to 'sourcecodes/bnt-master/KPMstats/multipdf.m')
-rw-r--r--sourcecodes/bnt-master/KPMstats/multipdf.m45
1 files changed, 45 insertions, 0 deletions
diff --git a/sourcecodes/bnt-master/KPMstats/multipdf.m b/sourcecodes/bnt-master/KPMstats/multipdf.m
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+function p = multipdf(x,theta)
+%MULTIPDF Multinomial probability density function.
+%   p = multipdf(x,theta) returns the probabilities of 
+%   vector x, under the multinomial distribution
+%   with parameter vector theta.
+%
+%   Author: David Ross
+
+%--------------------------------------------------------
+% Check the arguments.
+%--------------------------------------------------------
+error(nargchk(2,2,nargin));
+
+% make sure theta is a vector
+if ndims(theta) > 2 | all(size(theta) > 1)
+    error('theta must be a vector');
+end
+
+% make sure x is of the appropriate size
+if ndims(x) > 2 | any(size(x) ~= size(theta))
+    error('columns of X must have same length as theta');
+end
+
+
+%--------------------------------------------------------
+% Main...
+%--------------------------------------------------------
+p = prod(theta .^ x);
+p = p .* factorial(sum(x)) ./ prod(factorial_v(x));
+
+
+%--------------------------------------------------------
+% Function factorial_v(x): computes the factorial function
+% on each element of x
+%--------------------------------------------------------
+function r = factorial_v(x)
+
+if size(x,2) == 1
+    x = x';
+end
+
+r = [];
+for y = x
+    r = [r factorial(y)];
+end
\ No newline at end of file