You cannot simply substract these two matrices, becasue B contains integers (double), and A has strings.
You need to convert B to strings, and then you can use cat function to get the desired output.
A = {'A','B', 'C', 'D'};
B = [1 2 3 4; 5 6 7 8; 9 10 11 12; 13 14 15 16];
B_str=arrayfun(@num2str,B,'un',0);
C=arrayfun(@(index) strcat(A{index},'-',B_str(index,:)), 1:size(B,2),'uni',0);
output_matrix=cat(1,C{:})
