Returns the indices of points within a region

kdm_roi.pro

@@ -0,0 +1,24 @@
+function kdm_roi, x0, y0, x1, y1
+  o = obj_new('idlanroi', x0, y0 )
+  interior = o->containspoints( x1, y1 )
+  gd = where( interior ne 0, ngd )
+  if ngd eq 0 then MESSAGE, "No interior points found", /CONTINUE
+  obj_destroy, o
+  return, gd
+end
+
+;; test
+data_x = randomu( seed, 10, 10 ) * 10
+data_y = randomu( seed, 10, 10 ) * 10
+plot, data_x, data_y, /nodata
+plots, data_x, data_y, psym=2
+
+;; circle in the center
+x = findgen(100) * (!pi*(2/99.))
+y = sin(x)+5
+x = cos(x)+5
+oplot, x, y
+
+inside = kdm_roi( x, y, data_x, data_y )
+plots, data_x[inside], data_y[inside], color=253, psym=2
+end