How to subtract symbol associated matrix columnwise

A = [A; B; C; D]
B = [1 2 3 4; 5 6 7 8; 9 10 11 12; 13 14 15 16]
% my desired output is
C =
     A-1     A-2     A-3     A-4
     B-5     B-6     B-7     B-8
     C-9    C-10    C-11    C-12
    D-13    D-14    D-15    D-16
    
Thanks alot!  

Answer 1

[ANKUR KUMAR]

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{:})

output_matrix = 4×4 cell array
    {'A-1' }    {'A-2' }    {'A-3' }    {'A-4' }
    {'B-5' }    {'B-6' }    {'B-7' }    {'B-8' }
    {'C-9' }    {'C-10'}    {'C-11'}    {'C-12'}
    {'D-13'}    {'D-14'}    {'D-15'}    {'D-16'}

[Vincent Ike]

Thank you. You are very correct, although I was trying to relate the answer here to a question I asked ealier in https://www.mathworks.com/matlabcentral/answers/877563-solve-an-algebraic-matrix-equation. It is to solve a time dependent force function columnwise with A,B,C,D as the unknown variable, here converting the numeric to string may worsen my problem I think, cause I don't know much of MATLAB.

Answer 2

[Walter Roberson]

syms A B C D
A1 = [A; B; C; D]

A1 = 

B = [1 2 3 4; 5 6 7 8; 9 10 11 12; 13 14 15 16]

B = 4×4

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

A1 - B

ans = 

[Walter Roberson]

See also https://www.mathworks.com/matlabcentral/answers/877563-solve-an-algebraic-matrix-equation#answer_746223

[Vincent Ike]

You've been very helpful Walter. Many thanks!