Crossval for classification error

Hi, I'm trying to classify a dataset using lasso (not the built-in one function), I'm using a crossvalidation. The error I get is this:

Error using crossval> evalFun (line 488)
The function 'lasso_pred' generated the following error:
Undefined function 'minus' for input arguments of type 'nominal'.
Error in crossval> getLossVal (line 525)
funResult = evalFun (funorStr, arg (1: end-1));
Error in crossval (line 424)
                 [funResult, outarg] = getLossVal (i, nData, cvp, data, predfun);
Error in test (line 59)
cv_error_lasso = crossval ('mcr', X, y, 'Predfun', @lasso_pred, 'Partition', cvp_lasso);

Below I put the code:

cvp_lasso = cvpartition(y, 'LeaveOut');
cv_error_lasso = crossval('mcr', X, y, 'Predfun', @lasso_pred, 'Partition', cvp_lasso);

This is the funct:

function yfit = lasso_pred(Xtrain, ytrain, Xtest)
    B = lasso(Xtrain, ytrain);
    yfit = Xtest * B(:, end);
end

Thanks!

Answer 1

[Harsha Priya Daggubati]

Hi,

Similar question is asked in the following thread:

https://www.mathworks.com/matlabcentral/answers/46855-undefined-function-mtimes-for-input-arguments-of-type-nominal?s_tid=answers_rc1-2_p2_MLT