TMarker position incorrect for TH2F "cont4z" drawing?

ROOT
1

Hi

When I draw a TH2F using the “cont4z” option and then draw a TMarker object on the same pad, the position that I use to construct the marker is different than the one displayed. If instead I draw the TH2F with the “colz” option and then the TMarker, the position is correct.

Is there a change in the coordinate system the marker uses when the “cont4z” option is used?

I am using 5.28-00c on a linux rhel5-32 machine, but the behavior is the same using 5.26-00 on a SL4-32 machine. I have attached a macro that reproduces this issue on my machine which I compile with aclic. Is this the expected behavior?

Thank you,
Andy

markerTest.C (774 Bytes)

2

CONT4 is the SURF3 option seen from top. It has its own coordinate system.
Therefore the coordinates you see on the axis are not those used to draw the contours.
You need to put a transparent pad on top of the CONT4 drawing (with the right coordinates) in order to draw the marker at the right place.