谁能帮我用Matlba编程关于最小二乘法

function [pls_P,pls_Q,pls_W,pls_B]=pls_model(X_M, Y_M, iter)
% reference: Paul Geladi and Bruce R. Kowalski. Partial Least-Square Regression: A Tutorial. Analytica Chimica Acta,1986, 185:19

% Fundation
% X=TP'+E=∑tp'+E
% Y=UQ'+F=∑uq'+F
% u=bt[pls_P,pls_Q,pls_W,pls_B]=pls_model(X_M, Y_M, iter)
% b=u't/t't
% Y=TBQ'+F
% input
% X_M N by K the independant block, must be processed with meaning and scaling
% Y_M N by P the dependant block, must be processed with meaning and scaling
% iter-- the number of PLS components extracted
% output
% pls_P the loadings for every pls component of X
% pls_Q the loadings for every pls componentof Y
% pls_W the weights
% pls_B the regression coefficients for the inner relation.
[N,K]=size(X_M);
[N,P]=size(Y_M);
if iter > min(N,K)
iter = min(N,K);
end
% start algrithm: PLS
for counter = 1:iter; % extract