MATLAB: Evaluating symbolic matrix equations

Question

I have a symbolic matrix of size 20×3, which I have created using the sym() function. I have another matrix B which is calculated using certain rows of A, or in general the matrix B is a function of A i.e., . Once I obtain all the numerical entries of A, how can I evaluate B after substituting A with the obtained numerical values?

A = sym('a', [20, 3]);  % Create a 20x3 symbolic matrix
% Create a matrix B whose values depend on some function of A's elements
B(1, :) = cross(A(1, :), A(3, :));
B(2, :) = A(5, :) .* A(10, :) .* A(20, :);
% Substitute A with numerical values
A = subs(A, A, rand(20, 3));    % Now, A is a 20x3 matrix with random entries
% How do I evaluate the matrix B?
subs(B) ?
subs(B, A) ? % Both commands aren't working

Answer 1

After some hit and trials, I found the solution:

A = sym('a', [20, 3]);  % Create a 20x3 symbolic matrix
% Create a matrix B whose values depend on some function of A's elements
B(1, :) = cross(A(1, :), A(3, :));
B(2, :) = A(5, :) .* A(10, :) .* A(20, :);
% Substitute B with A, where A is substitued with 20x3 numerical entries:
B = subs(B, A, rand(20, 3));