Language Reference

ATAN(X)

Arctangent (inverse tangent) function.

X

must be of type real.

Class

Elemental function

Result Type and Attributes

Same as X.

Result Value

• It is expressed in radians and approximates arctan(X).

• It is in the range -pi/2 <= ATAN(X) <= pi/2.

Examples

ATAN (1.0) approximates pi/4.

Specific Name	Argument Type	Result Type	Pass As Arg?
ATAN	default real	default real	yes
DATAN	double precision real	double precision real	yes
QATAN	REAL(16)	REAL(16)	yes