Matlab While Loop problem

I want to do a while loop so given array A=[2, 4, 6;9, 10, 11; -1, -3 , 12). I want generate B whose elements are the natural logarithm of the values in A if the values are greater than 1. remaining elements of B can be obtained by adding 21 to each of the corresponding elements of A

Answer 1

[Image Analyst]

A vectorized solution:

A=[2, 4, 6;9, 10, 11; -1, -3 , 12] % Define input data.
B = A + 21 % Initialize B
moreThan1 = A > 1 % Find elements greater than 1.
B(moreThan1) = log(A(moreThan1)) % Assign them to log(A).

Answer 2

[Iain]

 count = 0
 while count < numel(a)
  count = count + 1;
  if a(count)>1
   b(count) = log(a(count));
  else
   b(count) = log(a(count)+21);
  end
 end

There are other, better, faster methods.

Answer 3

[Mehmet Mert Aktas]

clear clc a = [2, 4, 6; 9, 10, 11; -1, -3, -12]; b = zeros(size(a)); for i = 1: 3 for j = 1: 3 if (a(i,j) > 1) b(i,j) = log(a(i,j)); else b(i,j) = a(i,j) + 21; end end end