Why input data does not appear in "Inputs" list of Pattern Recognition GUI?

I have partitioned my data table into training and test sets. But, I do not know how to make the sets appear in the "Inputs" and "Targets" list of the Pattern Recognition GUI. I have used the following code from an online tutorial, I was hoping that Xtrain and Xtest show up in th e"Inputs" dropdown list.

%% Define variables to response and predictors

Y = MLtest.CLGrp_Diagnosis;

X = MLtest(:,5:40);

%%Cross Validations

cv = cvpartition(height(MLtest),'holdout',0.50);

%%Training set

Xtrain = X(training(cv),:);

Ytrain = Y(training(cv),:);

%% Convert Table to Inputs and Targets

ind = Ytrain';

vec = ind2vec(ind);

targets = full(vec);