em_invgausspdf.m

EM分群,matlab程式碼,用來分群用的

function y = EM_invgausspdf(x,par)
%INVGAUSSPDF Inverse Gaussian probability density function.
%   Y = INVGAUSSPDF(X,MU,LAM) returns the inverse gaussian probability density function 
%   with parameters MU and LAM, at the values in X.
%
%   The size of Y is the size of the X argument. (GENERALIZE)
%

%   References (CHECK OUT):
%      [1]  .....
% 
%   Created by Enrico Rossoni - 17/06/2004

mu = par(1);
lam = par(2);

% Initialize Y to zero.
y = zeros(size(x));

if mu>0 & lam>0
    y = sqrt(lam./(2*pi*x.^3)).*exp(-lam*((x-mu).^2)./(2*mu^2*x));
end