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: spm_mvNpdf.m
    path of file: ./repos/spm12
    
    the code of the file until where you have to start completion: function pdf = spm_mvNpdf(z,Mu,V)
% Probability Density Function (PDF) of multivariate Normal distribution
% FORMAT pdf = spm_Npdf(z,Mu,V)
%
% z  - ordinates
% Mu - mean (a d-vector)
% V  - d x d variance-covariance matrix
%__________________________________________________________________________
%
% spm_Npdf returns the Probability Density Function (PDF) for the
% multivariate Normal (Gaussian) family of distributions.
%
% The dimension of the Normal distribution is taken as the length of Mu.
% V must be a d x d variance-covariance matrix.
%
% For the univariate Normal distribution (d=1), z can be a matrix of
% arbitrary dimensions - each entry is treated seperately and the PDF
% returned as the corresponding element in a matrix of the same size.
%
% For multivarate PDFs, the ordinates must be in the columns of z, so
% z must have column dimension d. Multiple columns can be entered. 

    
function pdf = spm_mvNpdf(z,Mu,V)
% Probability Density Function (PDF) of multivariate Normal distribution
% FORMAT pdf = spm_Npdf(z,Mu,V)
%
% z  - ordinates
% Mu - mean (a d-vector)
% V  - d x d variance-covariance matrix
%__________________________________________________________________________
%
% spm_Npdf returns the Probability Density Function (PDF) for the
% multivariate Normal (Gaussian) family of distributions.
%
% The dimension of the Normal distribution is taken as the length of Mu.
% V must be a d x d variance-covariance matrix.
%
% For the univariate Normal distribution (d=1), z can be a matrix of
% arbitrary dimensions - each entry is treated seperately and the PDF
% returned as the corresponding element in a matrix of the same size.
%
% For multivarate PDFs, the ordinates must be in the columns of z, so
% z must have column dimension d. Multiple columns can be entered. 
%
%__________________________________________________________________________
% Copyright (C) 1998-2011 Wellcome Trust Centre for Neuroimaging

% Andrew Holmes
% $Id: spm_mvNpdf.m 4182 2011-02-01 12:29:09Z guillaume $


%-Condition arguments
%--------------------------------------------------------------------------
if nargin<1,   pdf=[]; return, end