Moving in an Array, Relative Location/Origin

Hello:

I am dealing with arrays that starts off at a location (x,y) on a grid (array) and then moving one space either to the left, right, up, or down. Then, I want to move again using the new coordinate (say, (xo,yo)), so it serves as the new origin. This is similar to doing Monte Carlo simulation. How can I do this using loops under I hit the axes? Thank you.

Answer 1

[Star Strider]

I’m not sure what you want to do, but it seems like a random walk. This should get you started, and you may need to experiment with it to get the result you want:

N = 100;                                % Size Of Matrix
A = randi(10, N, N);                    % Create Matrix
X0 = randi(N);                          % Initial Origin
Y0 = randi(N);
[Ar,Ac] = size(A);                      % Determine Limits
k1 = 1;                                 % Counter
XY(k1,:) = randi(N, 1, 3);              % Initial
while ((X0 > 1) && (X0 < Ac)) && ((Y0 > 1) && (Y0 < Ar))
    X0 = X0 + (-1)^randi(2);            % New ‘X0’
    Y0 = Y0 + (-1)^randi(2);            % New ‘Y0’
    XY(k1,:) = [X0,Y0,A(X0,Y0)];        % Record Moves & ‘A’ Values
    k1 = k1 + 1;
end

figure(1)
plot(XY(:,1), XY(:,2))
grid
axis([1  N    1  N])

[Jack Zhang]

Yes, it is essentially a random walk.

[Star Strider]

Did you run my code?

Does it do what you want it to?