http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49336
Summary: ATAN2 values differ from those specified in
documentation
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: minor
Priority: P3
Component: libfortran
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: ahn...@gmail.com
The documentation for ATAN2(Y,X) says:
"If Y is zero, then the return value is zero if X is positive and pi if X is
negative."
However, the value returned by ATAN2(-0d0, -1d0) is -pi (not +pi).
This is for gfortran 4.4.5.
So either the documentation needs fixing (and signed zero explained),
or the function ATAN2 should be redefined to return values in (-pi,pi].
...I'm not sure which is more standard for Fortran.
