function build_mat_files()
% This function creates mat files from Penn World Tables 6.3. (Alan Heston, Robert Summers and Bettina Aten, Penn World Table Version 6.3, 
% Center for International Comparisons of Production, Income and Prices at the University of Pennsylvania, August 2009).
%
% stephane DOT adjemian AT ens DOT fr
% Sun Nov 15 18:19:12 2009
    
first_year = 1950;
last_year  = 2007;
number_of_countries = 198;

nobs = last_year-first_year+1;
map  = zeros(number_of_countries,2);
map(:,1)  = transpose(0:(number_of_countries-1))*nobs+1;
map(:,2)  = transpose(1:number_of_countries)*nobs;

% List of country names
fid = fopen('pwt_names.csv','r');
tmp = textscan(fid,'%s','Delimiter','\n');
fclose(fid);
[junk,n,m] = unique(tmp{1});
names = tmp{1}(sort(n),:);
names = cell2mat(names);
save('pwt_names.mat','names','map');

% List of country codes
fid = fopen('pwt_codes.csv','r');
tmp = textscan(fid,'%s','Delimiter','\n');
fclose(fid);
[junk,n,m] = unique(tmp{1});
codes = tmp{1}(sort(n),:);
codes = cell2mat(codes);
save('pwt_codes.mat','codes','map');

% List of variables
fid = fopen('pwt_variables.csv','r');
tmp = textscan(fid,'%s','Delimiter','\n');
fclose(fid);
variables = cell2mat(tmp{1});
save('pwt_variables.mat','variables');

% data
pwt = load('pwt63.csv','-ascii');
save('pwt63.mat','pwt');