hpux man page for atan2f

atan2(3M)																 atan2(3M)

NAME
       atan2(), atan2f(), atan2l(), atan2w(), atan2q() - arctangent and quadrant functions

SYNOPSIS
   HP Integrity Server Only
DESCRIPTION
       returns the arctangent of y/x, using the signs of both arguments to determine the quadrant of the return value.

       is a version of it takes arguments and returns a result.

   Integrity Server Only
       is a version of it takes arguments and returns a result.

       is an version of it takes arguments and returns an result.

       is equivalent to on HP-UX systems.

USAGE
       To use these functions, compile either with the default option or with the and the options.

       To use (for Integrity servers) or compile also with the option.

       To use any of these functions, make sure your program includes and link in the math library by specifying on the compiler or linker command
       line.

       For more information, see the at the following site:

   PA-RISC Only
       Millicode versions of the function are available.  Millicode versions of math library functions are usually faster than their  counterparts
       in the standard library.  To use these versions, compile your program with the or the optimization option.

       For special cases, the millicode versions return the same values as their standard library counterparts (see the section).

RETURN VALUE
       If y and x is -0

       If y and x is +0

       If y and x is less than zero, returns

       If y and x is greater than zero, returns

       If y is less than zero and x is zero, returns

       If y is greater than zero and x is zero, returns

       If y is greater than zero and x is -INFINITY, returns Pi.

       If y is less than zero and x is -INFINITY,

       If y is greater than zero and x is INFINITY, returns +0.

       If y is less than zero and x is INFINITY, returns -0.

       If y and x is finite, returns

       If y and x is -INFINITY, returns

       If y and x is +INFINITY, returns

       If x or y is NaN, returns NaN.

       Whether raises the inexact exception is unspecified.

ERRORS
       No errors are defined.

SEE ALSO
       acos(3M), asin(3M), atan(3M), atan2d(3M), carg(3M), cos(3M), sin(3M), tan(3M), math(5).

STANDARDS CONFORMANCE
       : SVID3, XPG4.2, ANSI C, ISO/IEC C99 (including Annex F, ``IEC 60559 floating-point arithmetic'')

       : ISO/IEC C99 (including Annex F, ``IEC 60559 floating-point arithmetic'')

																	 atan2(3M)