Check if turtles have same x-coordinate and y-coordinate as patches

问题

I have a patchset subtractset and some of patches have turtles on it.

Now, I wish to create turtles on only those patches which have different x-cor and y-cor as the patches.

Note: This is different from below code:

  distribute-turtles (population * percent) subtractset with[count turtles-here = 0]

as here a turtle maybe on patch and still have different x-cor and y-cor as the patch.

Thanks. Please let me if there is some ambiguity in my question.

回答1:

Patches have integer coordinates so one way would be to check if the turtles coordinates are integers. round xcor = xcor and round ycor = ycor

Is true iff the turtle is centered on a patch

Or because turtles have access to patch variables

 xcor = pxcor and ycor = pycor

Which is more pleasing to my eye and probably faster.

You could put it in a procedure.

To-report centered 
    Report xcor = pxcor and ycor = pycor
End

来源：https://stackoverflow.com/questions/26690556/check-if-turtles-have-same-x-coordinate-and-y-coordinate-as-patches