Index: trunk/ippScripts/scripts/magic_tree.pl
===================================================================
--- trunk/ippScripts/scripts/magic_tree.pl	(revision 24174)
+++ trunk/ippScripts/scripts/magic_tree.pl	(revision 26183)
@@ -169,5 +169,8 @@
     # Coordinates on rotated celestial sphere
     my $phi = atan2($eta,$xi) + pi/2;
-    my $theta = atan(180 / pi / sqrt($xi**2 + $eta**2));
+    my $denominator = sqrt($xi**2 + $eta**2);
+    &my_die("denominator is zero!!", $magic_id, $PS_EXIT_PROG_ERROR) if $denominator == 0;
+
+    my $theta = atan(180 / pi / $denominator);
 
     # Coordinates on celestial sphere