Index: trunk/Ohana/src/opihi/cmd.astro/region.c
===================================================================
--- trunk/Ohana/src/opihi/cmd.astro/region.c	(revision 42821)
+++ trunk/Ohana/src/opihi/cmd.astro/region.c	(revision 42942)
@@ -35,4 +35,6 @@
     KapaGetImageCoords (kapa, &graphmode.coords);
     KapaGetImageRange (kapa, &graphmode.xmin, &graphmode.xmax, &graphmode.ymax, &graphmode.ymin, &dXpix, &dYpix);
+    // XXX here (xmin,xmax),(ymin,ymax) are ???
+    // below, (xmin,xmax),(ymin,ymax) are set to put 0,0 in the graph center (-dx to +dx)
 
     set_variable ("XMIN", graphmode.xmin);
@@ -40,5 +42,5 @@
     set_variable ("YMIN", graphmode.ymin);
     set_variable ("YMAX", graphmode.ymax);
-
+    // XXX Ra,Dec not defined at this point
     set_variable ("RMIN", Ra  + graphmode.xmin);
     set_variable ("RMAX", Ra  + graphmode.xmax);