ATAN Function

Returns the arc tangent.

Category:

Trigonometric

Syntax

ATAN (argument)

Required Argument

argument

specifies a numeric constant, variable, or expression.

Details

The ATAN function returns the 2-quadrant arc tangent (inverse tangent) of the argument. The value that is returned is the angle (in radians) whose tangent is x and whose value ranges from -

π / 2

π / 2

. If the argument is missing, then ATAN returns a missing value.

Comparisons

The ATAN function is similar to the ATAN2 function except that ATAN2 calculates the arc tangent of the angle from the ratio of two arguments rather than from one argument.

Example

The following SAS statements produce these results.

SAS Statement	Result
x=atan(0);	0
x=atan(1);	0.7853981634
x=atan(-9.0);	-1.460139106