How do I code for this random situation?

On a r*c size grid, 55% of the sites are randomly filled with X, 2% randomly filled with Y, and the rest are empty

[John D'Errico]

Geez. WIll you stop changing your questions as fast as you can? I commented on your last question. Then I answered this one, in its previous incarnation, only to see you had comepletely changed the question. I deleted my answer to the last question, and now I'm done.

[NAA]

There was no previous question like this, and I saw your comment on the other question, you didn't answer. Instead you just left a rude comment like the one here

[Image Analyst]

@NAA, OK try it this way:

r = 10;
c = 20;
output = nan(r, c);
numX = round(0.55 * r * c) % Number of elements to place an X into.
numY = round(0.02 * r * c) % Number of elements to place a Y into.
X = 1;
Y = 2;
output(1 : numX) = X;
output(numX + 1 : numX + numY) = Y;
randomIndexes = randperm(numel(output));
output = reshape(output(randomIndexes), [r, c])

There are other ways that would work also.

Answer 1

[Image Analyst]

This looks like a homework problem. If you have any questions ask your instructor or read the link below to get started:

How do I get help on homework questions on MATLAB Answers? - MATLAB Answers - MATLAB Central

Obviously we can't give you the full solution because you're not allowed to turn in our code as your own.

Hint:

output = nan(r, c);
numX = round(0.55 * r * c); % Number of elements to place an X into.
numY = round(0.02 * r * c); % Number of elements to place a Y into.

Two ways to do it:

1. You can do it vectorized using randperm (assign the X to the first numX elements, then assign Y to the next numY elements, then use randperm to scramble the order), or
2. you can do it brute force using a for loop to place the x value and another loop to place the Y value, but only in the location if the value is a nan (not an X).

[NAA]

it's not the hw problem, this is just part of an assumption I am making to get started, but thank you!