fixed divisibility test per discussion with GB

TCL/polarDensity_for_DTA.tcl

@@ -583,12 +583,9 @@ proc polarDensityBin { config_file_script } {
     source $params(utils)/BinTools.tcl
 
     ;# check to make sure Rmax is evenly divisible by dr.
-    ;# Cannot ensure that Rmax and dr are both ints, so divisibility_test
-    ;# multiplies both by 10,000 before converting to int as a reasonable
-    ;# precaution. Specifying Rmax and dr to greater than 5 decimal places is
-    ;# a questionable life choice.
-    set divisibility_test [expr [expr int([expr $params(Rmax) * 10000])] % [expr int([expr $params(dr) * 10000])]]
-    if {$divisibility_test != 0} {
+    set divisibility_test [expr [expr double($params(Rmax))] % [expr double($params(dr))]]
+    set TOLERANCE [expr 10**-12]
+    if {$divisibility_test >= $TOLERANCE} {
         error "Rmax must be evenly divisible by dr."
     }