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atan2

See the current Perl documentation for atan2.

Here is our local, out-dated (pre-5.6) version:


atan2 - arctangent of Y/X



atan2 Y,X



Returns the arctangent of Y/X in the range -PI to PI.

For the tangent operation, you may use the POSIX::tan() function, or use the familiar relation:

    sub tan { sin($_[0]) / cos($_[0])  }