squares moving error in matlab

so i am trying to write a code i want to move squares in other squares randomly,there is 10x10 squares. squares move but i dont know my code is true can you help? i cant share the whole code, because its a school project, i just want to know if this makes sense, its something like this (i added particle poisitons because i think thats the whole point and i forgot)

particle_positions = ones(num_of_particles, 2) * num_of_cells / 2 + 0.5
...
     move_x = randi([-1, 1]);
...
    if xnew < 1
    xnew > num_of_cells ;
    move_x = -move_x;
end

Answer 1

[Image Analyst]

This doesn't make any sense:

if xnew < 1
    xnew > num_of_cells ;
    move_x = -move_x;
end

It should be something like

if xnew < 1
    % Don't let it go from 1 to 0
    xnew = 1;
elseif xnew > num_of_cells
    distancePast = xnew - num_of_cells;
    xnew = num_of_cells - distancePast;
end

[Image Analyst]

Are you keeping track of the locations on integers, or on the 0.5 marks? Maybe just put gridlines on but use xline() and yline() to make the other gridlines at the 0.5 locations.

[nctt]

I want the squares to match the squares in the grid.. I used xline yline but its still the same

[Image Analyst]

Then you need to make sure the centers are on the 0.5 locations and go from the integer less than that to the integer more than that.