Question

I have 2 matrices in Matlab, A and B, I am trying to find an easy way to take these in and output a function that maps A to B, it should be as easy as a function in the form of B=Ax+y where x and y are static numbers, but I cannot seem to remember my basic math skills today. Is there an easy way of doing this in Matlab?

Answer 1

Edit

This is the answer to the OP’s original question as explained in the comments.

Take two elements b1 and b2 from B and the same elements a1 and a2 from A. Be sure that a1 ~= a2. If all elements of A are the same then the problem is trivial. Then compute

x = (b1-b2) / (a1-a2) ;
y = b1 - a1*x;
err = B - A*x - y;
total_error = sum(abs(err(:)));

If x and y do not satisfy the equation, then total_error > 0 and there is no such x and y.

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Actually, if x and y are just numbers, you can just do

B = A*x + y;

Matlab is capable of doing matrix times scalar arithmetic by broadcasting the number x to each element of A.

If x is a vector and A*x makes sense, you can do the same.

If y is a scalar or a vector of the same size as A*x, you can also do the same.