MATLAB: Error using cross validation with plsregress

cross-validationplsregress

Hi everyone,

I am running a PLS regression and try to perform cross validation (k-fold) with matlab data.

load spectra
X = NIR;
y = octane;
[XL,yl,XS,YS,beta,PCTVAR,MSE] = plsregress(X,y,10,'CV',10);

Unfortunately, this error appear:

Could you explain to me how to solve it please?

Thank you in advance for your help.

Bruno

Best Answer

Based on the results of

which crossval -all

a function with the same name from a 3rd party toolbox (pls toolbox) is shadowing Matlab's crossval function which is called by plsregress.

If you are not using the pls toolbox, remove it from your Matlab path using

rmpath('C:\Program Files\MATLAB\R2017a\toolbox\pls_toolbox_862')
% or 
rmpath([matlabroot, '\toolbox\pls_toolbox_862'])

If you are using the pls toolbox, you can use Julian's answer explained here

https://www.mathworks.com/matlabcentral/answers/149059-how-do-i-invoke-a-shadowed-core-matlab-function-not-built-in-from-an-overloaded-function-of-same

It grabs the function handle from Matlab's crossval function and assigns it to a variable that you can use in addition to the crossval version in pls toolbox.