Deroulement un prgm matlab

bonjour
j'ai ce programme matlab et je suis null en ce language on nous a demandé de derouler cet algorithme et je dois rendre le rapport ce jeudi est ce que vous pouvez m'aider a me dire ce quil fait ce programme?

[nobs nvar] = size(x);
fid = 1;
% error checking on inputs
if nargin == 3
nflag = 1;
elseif nargin == 2
nflag = 1;
fmt = '%10.2f';
elseif nargin == 1
nflag = 0;
fmt = '%10.2f';
else
error('Wrong # of arguments to bkw');
end;

[u d v] = svd(x,0);

lamda = diag(d(1:nvar,1:nvar));
lamda2 = lamda.*lamda;
v = v.*v;

phi = zeros(nvar,nvar);
for i=1:nvar;
phi(i,:) = v(i,:)./lamda2';
end;


pi = zeros(nvar,nvar);
for i=1:nvar;
phik = sum(phi(i,:));
pi(i,:) = phi(i,:)/phik;
end;

% BUG fix suggested by
% John P. Burkett <burkett@uriacc.uri.edu
lmax = lamda(1);
lmaxvec = lmax*ones(nvar,1);
lout = lmaxvec./lamda;


out = pi';

% make up some generic names
Vname = [];
for i=1:nvar
if i < 10
snames = 'var ';
name = [snames num2str(i)];
Vname = [Vname
name];
else
snames = 'var';
name = [snames num2str(i)];
Vname = [Vname
name];
end;
end;
if nflag == 1
[namsiz nsize] = size(vnames); % error check vnames argument
if namsiz == nvar+1
Vname = [];
for i=1:nvar
Vname = strvcat(Vname,vnames(i+1,:));
end;
elseif namsiz == nvar
Vname = [];
for i=1:nvar
Vname = strvcat(Vname,vnames(i,:));
end;
else
fprintf(fid,'Wrong # of variable names in bkw -- check vnames argument \n');
fprintf(fid,'will use generic variable names \n');
end; % end of if-elseif,else
end; % end of if

rnames = strvcat('K(x)',num2str(round(lout)));
in.fmt = fmt;
in.rnames = rnames;
in.cnames = Vname;
fprintf('\n Belsley, Kuh, Welsch Variance-decomposition \n');
mprint(out,in);

merci d'avance