alternative of ismember function

I need to replace ismember in this program with equivalent function(not inbuild),any ideas?

x=randi([1, M-h],1,1);  % M,N size of image and h,w dimension of rectangle
y=randi([1 ,N-w],1,1);
if ismember(Vf,I(x:x+h,y:y+w))
  fail_count=fail_count+1;

I'm generating non overlapping rectangles,here ismember is checking wthether point x,y lies inside a rectangle or not.

I(x:x+h,y:y+w)) is rectangle.

[Walter Roberson]

That code is checking to see if the value of Vf is the same as any of the pixel values stored in I(x:x+h, y:y+w) . That would not check to see whether x, y lies inside a rectangle.

In the case where you are using I to record the rectangles that have already been drawn, then if you use true to indicate a location already filled, then

if any(any(I(x:x+h, y:y+w)))
    %it overlaps with something that is already filled
end

[Guillaume]

I need to replace ismember

Why? How can we know what's acceptable if you don't tell us why ismember is not acceptable.