ensureMeanAndCov

 ensure proper mean and covariance

 THIS IS NO USER FUNCTION

• discretizeDistribution discretize a continuous distribution
• obtainDistributionContinuous obtain the density function for a distribution
• obtainDistributionDiscrete obtain a discrete probability distribution

0001 function [mean, cov] = ensureMeanAndCov(nDim, mean, cov)
0002 % ensure proper mean and covariance
0003 %
0004 % THIS IS NO USER FUNCTION
0005 
0006 % The elk-library: convex geometry applied to crystallization modeling.
0007 %   Copyright (C) 2013 Alexander Reinhold
0008 %
0009 % This program is free software: you can redistribute it and/or modify it
0010 %   under the terms of the GNU General Public License as published by the
0011 %   Free Software Foundation, either version 3 of the License, or (at your
0012 %   option) any later version.
0013 %
0014 % This program is distributed in the hope that it will be useful, but
0015 %   WITHOUT ANY WARRANTY; without even the implied warranty of
0016 %   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
0017 %   General Public License for more details.
0018 %
0019 % You should have received a copy of the GNU General Public License along
0020 %   with this program.  If not, see <http://www.gnu.org/licenses/>.
0021 
0022 %% mean
0023 mean = mean(:);
0024 if ~isempty(nDim) && numel(mean) ~= nDim
0025     error('elk:distribution:wrongInput', ...
0026         'Mean vector has improper dimension');
0027 else
0028     nDim = numel(mean);
0029 end
0030 
0031 %% cov
0032 if (size(cov, 1) == nDim) && (size(cov, 2) == nDim)
0033     % everything OK
0034 elseif numel(cov) == 1
0035     cov = cov*eye(nDim);
0036 elseif numel(cov) == nDim
0037     % this case assumes that the std is provided
0038     cov = diag(cov);
0039 else
0040     error('elk:distribution:wrongInput', ['Covariance matrix does not ' ...
0041         'match the dimension of the continuous distribution']);
0042 end