diff options
| author | ziejd2 | 2017-09-28 15:04:40 -0500 |
|---|---|---|
| committer | ziejd2 | 2017-09-28 15:04:40 -0500 |
| commit | 8070dc963753142bb86c4ed698d91fd623ed28e7 (patch) | |
| tree | d0f6dd8fc46a49b819aa55c1a90faa14d8448883 /sourcecodes/bnt-master/KPMstats/dirichletpdf.m | |
| parent | 7cc31810d53176e805532b2789955f4eedbce6bb (diff) | |
| download | BNW-8070dc963753142bb86c4ed698d91fd623ed28e7.tar.gz | |
BNW using Octave instead of Matlab.
This version of BNW should perform the same as the original version. The only difference is that it uses Octave instead of Matlab when running BayesNet Toolbox during parameter learning. I am calling this BNW_1.02. It can be accessed at: compbio.uthsc.edu/BNW_1.02
Diffstat (limited to 'sourcecodes/bnt-master/KPMstats/dirichletpdf.m')
| -rw-r--r-- | sourcecodes/bnt-master/KPMstats/dirichletpdf.m | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/sourcecodes/bnt-master/KPMstats/dirichletpdf.m b/sourcecodes/bnt-master/KPMstats/dirichletpdf.m new file mode 100644 index 00000000..8b789844 --- /dev/null +++ b/sourcecodes/bnt-master/KPMstats/dirichletpdf.m @@ -0,0 +1,39 @@ +function p = dirichletpdf(x, alpha) +%DIRICHLETPDF Dirichlet probability density function. +% p = dirichletpdf(x, alpha) returns the probability of vector +% x under the Dirichlet distribution with parameter vector +% alpha. +% +% Author: David Ross + +%------------------------------------------------- +% Check the input +%------------------------------------------------- +error(nargchk(2,2,nargin)); + +% enusre alpha is a vector +if min(size(alpha)) ~= 1 | ndims(alpha) > 2 | length(alpha) == 1 + error('alpha must be a vector'); +end + +% ensure x is is a vector of the same size as alpha +if any(size(x) ~= size(alpha)) + error('x and alpha must be the same size'); +end + + +%------------------------------------------------- +% Main +%------------------------------------------------- +if any(x < 0) + p = 0; +elseif sum(x) ~= 1 + disp(['dirichletpdf warning: sum(x)~=1, but this may be ' ... + 'due to numerical issues']); + p = 0; +else + z = gammaln(sum(alpha)) - sum(gammaln(alpha)); + z = exp(z); + + p = z * prod(x.^(alpha-1)); +end \ No newline at end of file |
