Accuracy Calculation using confusionmat?

Kindly I have an issue with accuracy calculation, please could you help ?

y_train = [ 1 1 1 4 4 3 3 5 5 5 ]; % for x_train

%x_test : has no true labels.

predictedLabel=[ 1 2 3 4 5 ]; %predicted lables for x_test

I used the code below :

group=y_train ; % 10
grouphat=predictedLabel; % for test 5 test data
C=confusionmat(group,grouphat);
Accuracy = sum ( diag (C)) / sum (C (:)) ×100;

but get error:

Error using confusionmat (line 75)

G and GHAT need to have same number of rows

I had error since the test data is more or less than the train ( no lables)?

No true label for test data ( semi supervised learning )

Thank you