You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: gmmunpak.m
    path of file: ./repos/pcm/matlab/lib/netlab3_3
    
    the code of the file until where you have to start completion: function mix = gmmunpak(mix, p)
%GMMUNPAK Separates a vector of Gaussian mixture model parameters into its components.
%
%	Description
%	MIX = GMMUNPAK(MIX, P) takes a GMM data structure MIX and  a single
%	row vector of parameters P and returns a mixture data structure
%	identical to the input MIX, except that the mixing coefficients
%	PRIORS, centres CENTRES and covariances COVARS  (and, for PPCA, the
%	lambdas and U (PCA sub-spaces)) are all set to the corresponding

    
function mix = gmmunpak(mix, p)
%GMMUNPAK Separates a vector of Gaussian mixture model parameters into its components.
%
%	Description
%	MIX = GMMUNPAK(MIX, P) takes a GMM data structure MIX and  a single
%	row vector of parameters P and returns a mixture data structure
%	identical to the input MIX, except that the mixing coefficients
%	PRIORS, centres CENTRES and covariances COVARS  (and, for PPCA, the
%	lambdas and U (PCA sub-spaces)) are all set to the corresponding
%	elements of P.
%
%	See also
%	GMM, GMMPAK
%

%	Copyright (c) Ian T Nabney (1996-2001)

errstring = consist(mix, 'gmm');
if ~errstring
  error(errstring);
end