ATAN(3f)

DESCRIPTION
ATAN(X) computes the arctangent of X.

STANDARD
Fortran 77 and later, for a complex argument and for two arguments Fortran 2008 or later

CLASS
Elemental function

SYNTAX

RESULT = ATAN(X) RESULT = ATAN(Y, X)

ARGUMENTS

X The type shall be REAL or COMPLEX; if Y is present, X shall be REAL. Y shall be of the same type and kind as X.

RETURN VALUE
The return value is of the same type and kind as X. If Y is present, the result is identical to ATAN2(Y,X). Otherwise, it the arcus tangent of X, where the real part of the result is in radians and lies in the range -PI/2 <=q Re atan(x) <=q PI/2.

EXAMPLE
          program test_atan
            real(8) :: x = 2.866_8
            x = atan(x)
          end program test_atan

SPECIFIC NAMES

Name Argument Return type Standard ATAN(X) REAL(4) X REAL(4) Fortran 77 and later DATAN(X) REAL(8) X REAL(8) Fortran 77 and later

SEE ALSO
Inverse function: TAN

AUTHOR

This information was taken from the GFortran documentation (https://gcc.gnu.org/onlinedocs/gcc-5.3.0/gfortran/) and converted to a manpage by AstroFloyd (http://astrofloyd.org).