function y=pdf(obj,X)
% PDF PDF for a Gaussian mixture distribution.
%    Y = PDF(OBJ,X) returns Y, a vector of length N containing the
%    probability density function (PDF) for the gmdistribution OBJ,
%    evaluated at the N-by-D data matrix X. Rows of X correspond to points,
%    columns correspond to variables. Y(I) is the PDF value of point I.
%
%    See also GMDISTRIBUTION, GMDISTRIBUTION/CDF.

%   Copyright 2007 The MathWorks, Inc.
%   $Revision: 1.1.6.2 $  $Date: 2007/06/14 05:26:23 $

% Check for valid input
if nargin ~= 2
    error('stats:gmdistribution:pdf:TooFewInputs',...
        'Two input arguments are required.');
end

checkdata(X,obj);

covNames = { 'diagonal','full'};
CovType = strmatch(lower(obj.CovType),covNames);
log_lh=wdensity(X,obj.mu, obj.Sigma, obj.PComponents, obj.SharedCov, CovType);
y =  sum(exp(log_lh),2);