+-------------------------------IBM Extension--------------------------------+

ATAN2D(Y, X)

Purpose

Arctangent (inverse tangent) function. The result is the principal value of the nonzero complex number (X, Y) formed by the real arguments Y and X.

Class

Elemental function

Argument Type and Attributes

Y
must be of type real.

X
must be of the same type and kind type parameter as Y. If Y has the value zero, X must not have the value zero.

Result Type and Attributes

Same as X.

Result Value

Examples

ATAN2D (1.5574077, 1.0) has the value 57.295780181 (approximately).

Given that:

Y = |  1.0   1.0 |   X = | -1.0   1.0 |
    | -1.0  -1.0 |       | -1.0   1.0 |

then the value of ATAN2D(Y,X) is:

ATAN2D(Y,X) =  |  135.0000000   45.00000000 |
               | -135.0000000  -45.00000000 |


Specific Name Argument Type Result Type Pass As Arg?
ATAN2D default real default real yes
DATAN2D double precision real double precision real yes
QATAN2D REAL(16) REAL(16) yes

+----------------------------End of IBM Extension----------------------------+

IBM Copyright 2003