Cannot draw arrow and add text

ROOT
2 
   TArrow *arrow = new TArrow(570, 3500, 525, 1200, 0.03, "|>");
   arrow->Draw();
   TLatex *text = new TLatex(510, 1000, "#splitline{here}{it is}");
   text->Draw();
   mycanvas->Modified(); mycanvas->Update(); // make sure it's really (re)drawn

See the subsections “The Coordinate Systems of a Pad” and “Converting between Coordinate Systems” in: ROOT User’s Guide -> Graphics and the Graphical User Interface -> Graphical Containers: Canvas and Pad