in-radius 1.0

agentset in-radius number

Reports an agentset that includes only those agents from the original agentset whose distance from the caller is less than or equal to number. (This can include the agent itself.)

The distance to or a from a patch is measured from the center of the patch.

ask turtles
  [ ask patches in-radius 3
      [ set pcolor red ] ]
;; each turtle makes a red "splotch" around itself