CODE:
function [r,rmsecv,yp] = loocv2(x,y,lv,sel)
if nargin <4;sel = 1;end
T = size(x,1);
yp = zeros(size(y));
for i = 1:T
x1 = x(i,:);
ind = 1:T;ind(i) = [];
x2 = x(ind,:);
y2 = y(ind,:);
if eq(sel,0)
[x2,mx] = mncn(x2);
x1 = scale(x1,mx);
[y2,my] = mncn(y2);
elseif eq(sel,1)
[x2,mx,stdx] = auto(x2);
x1 = scale(x1,mx,stdx);
[y2,my,stdy] = auto(y2);
end
b = simpls(x2,y2,lv);
yp0 = x1 * b(:,lv);
if eq(sel,0)
yp0 = rescale(yp0,my);
elseif eq(sel,1)
yp0 = rescale(yp0,my,stdy);
end
yp(i) = yp0;
end
r = corr(yp,y);
rmsecv = rms(y-yp);
function [mcx,mx] = mncn(x)
%MNCN Mean center scales matrix to mean zero.
% Mean centers matrix (x), returning a matrix with
% mean zero columns (mcx) and the vector of means
% (mx) used in the scaling.
%
%I/O: [mcx,mx] = mncn(x);
%
%See also: AUTO, MDAUTO, MDMNCN, MDRESCAL, MDSCALE, SCALE, RESCALE
%Copyright Eigenvector Research 1991-98
%Modified 11/93
%Checked on MATLAB 5 by BMW 1/4/97
[m,n] = size(x);
mx = mean(x);
mcx = (x-mx(ones(m,1),:));
function sx = scale(x,means,stds)
%SCALE Scales matrix as specified.
% Scales a matrix (x) using means (mx) and standard
% deviations (stds) specified.
%
%I/O: sx = scale(x,mx,stdx);
%
% If only two input arguments are supplied then the function
% will not do variance scaling, but only vector subtraction.
%
%I/O: sx = scale(x,mx);
%
%See also: AUTO, MDAUTO, MDMNCN, MDRESCAL, MDSCALE, MNCN, RESCALE
%Copyright Eigenvector Research, Inc. 1991-98
%Modified 11/93
%Checked on MATLAB 5 by BMW 1/4/97
[m,n] = size(x);
if nargin == 3
sx = (x-means(ones(m,1),:))./stds(ones(m,1),:);
else
sx = (x-means(ones(m,1),:));
end
function rx = rescale(x,mx,stdx)
%RESCALE Rescales matrix
% Rescales a matrix (x) using the means (mx) and
% standard deviation (stdx) vectors specified.
%
%I/O: rx = rescale(x,mx,stdx);
%
% If only two input arguments are supplied the
% function rescales the means only.
%
%I/O: rx = rescale(x,mx);
%
%See also: AUTO, MDAUTO, MDMNCN, MDRESCAL, MDSCALE, MNCN, SCALE
%Copyright Eigenvector Research, Inc. 1991-98
%Modified 11/93
%Checked on MATLAB 5 by BMW 1/4/97
[m,n] = size(x);
if nargin == 3
rx = (x.*stdx(ones(m,1),:))+mx(ones(m,1),:);
else
rx = x+mx(ones(m,1),:);
end
function [ax,mx,stdx] = auto(x)
%AUTO Autoscales matrix to mean zero unit variance
% Autoscales a matrix (x) and returns the resulting matrix (ax)
% with mean-zero unit variance columns, a vector of means (mx)
% and a vector of standard deviations (stdx) used in the scaling.
%
%I/O: [ax,mx,stdx] = auto(x);
%
%See also: MDAUTO, MDMNCN, MDRESCAL, MDSCALE, MNCN, SCALE, RESCALE
%Copyright Eigenvector Research, Inc. 1991-98
%Modified 11/93
%Checked on MATLAB 5 by BMW 1/4/97
[m,n] = size(x);
mx = mean(x);
stdx = std(x);
ax = (x-mx(ones(m,1),:))./stdx(ones(m,1),:);