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_mlm_makecon.m
    path of file: ./repos/spm12/toolbox/mlm
    
    the code of the file until where you have to start completion: function [con_vec] = spm_mlm_makecon (mlm,w)
% Make contrast to test if the subset of coefficients indexed by w = 0 ?
% FORMAT [con_vec] = spm_mlm_makecon (mlm,w)
%
% mlm           MLM data structure containing
%               [p x d] matrix of regression coefficients mlm.wmean
% w             [p x d] matrix of comprising 1's and 0's with

    
function [con_vec] = spm_mlm_makecon (mlm,w)
% Make contrast to test if the subset of coefficients indexed by w = 0 ?
% FORMAT [con_vec] = spm_mlm_makecon (mlm,w)
%
% mlm           MLM data structure containing
%               [p x d] matrix of regression coefficients mlm.wmean
% w             [p x d] matrix of comprising 1's and 0's with
%               1s selecting the coefficients of interest
%
% con_vec       Vectorised contrast matrix that can be passed 
%               to spm_mlm_posthoc.m
%
%___________________________________________________________________________
% Copyright (C) 2011 Wellcome Trust Centre for Neuroimaging

% Will Penny 
% $Id: spm_mlm_makecon.m 4651 2012-02-09 16:03:39Z will $

[p,d]=size(mlm.wmean);

con_vec=[];
for i=1:p,
    for j=1:d,
        if w(i,j)==1
            con=zeros(p,d);
            con(i,j)=1;
            con_vec=[con_vec;con(:)'];
        end