You thought right. It was kinda what i was trying to achieve. to paint or not determined points.
i checked the demo( did some tests, kinda apply it to my charts ) but still there is one more type i think.. or i dunno how to make the "right" expression:
the case is : when i build my dataset, i define "certain points" to be or not be paint accordinly with a flag inside the database ..i did it using annotations with a List with which to "paint or not".
so, basically i need to compare or check a list with the coordinates to paint or not...
that is being the biggest problem so far
Phillip