How to create a matrix of values from an if statement?

I have created a simulation of a predator carrying out a random walk in a 10x10 area, and when it encounters a stationary prey it stops. I want to create a histogram of i, which shows the distribution of how long it takes for the predator to encounter the prey. However, I cannot find a way to create a matrix containing the values of i. (The current output of histogram(i) is incorrect.)

I want to know how I can create a matrix of the values of i that are outputted from the if statement, so that I can create the histogram?

Here's my current code:

A = [randi(10), randi(10)];  %Random prey coordinates

m = 30; % number of predators being simulated
hold on;
for  j = 1:m
    n = 1000; % number of timesteps
    x = zeros(1,n+1);
    y = zeros(1,n+1);

      x(1) = randi(10);
      y(1) = randi(10);

      for i = 2:n+1 %making the predator go up\down 1 each step
          x(i) = x(i-1) + (randi(3)-2); 
          y(i) = y(i-1) + (randi(3)-2);

%Adding periodic boundary conditions
        if x(i) == -1
            x(i) = 10;
        end
        if x(i) == 11
            x(i) = 0;
        end
        if y(i) == -1
            y(i) = 10;
        end
        if y(i) == 11
            y(i) = 0;
        end
   if [randi(10), randi(10)] == [x(i), y(i)] %if the path of the predator encounters the coordinates of the prey, end the loop and output i
        i
        break %ends this loop only 
    end

      end
  end

histogram(i)

Answer 1

[Jos (10584)]

The statement [randi(10), randi(10)] will change every time, moving the prey randomly around the field. Set the position of the prey before the loop in which you move the predator

preyX = randi(10)

Secondly you want to store te value of i when the predator hits the prey, so i can be used again for the next loop

if ...
  result(j) = i ;
  break % break out of inner loop
end

Pre-allacting the result before the outer loop is recommended:

result = zero(m,1);

After all simulations are done, use:

    histogram (result)