Skip to main content

This is documentation for Caché & Ensemble.

For information on converting to InterSystems IRIS, see the InterSystems IRIS Adoption Guide and the InterSystems IRIS In-Place Conversion Guide, both available on the WRC Distributions page (login required).

Previous sectionNext section


A scalar numeric function that returns the arc-tangent, in radians, of the tangent of an angle.


{fn ATAN(float-expression)}


Argument Description
float-expression An expression of type float. This is the tangent of the angle.


ATAN takes any numeric value and returns the inverse (arc) of the tangent of an angle as a floating point number. ATAN returns NULL if passed a NULL value. ATAN treats nonnumeric strings, including the empty string (''), as the numeric value 0.

ATAN returns a value of data type FLOAT with a precision of 36 and a scale of 18.

ATAN can only be used as an ODBC scalar function (with the curly brace syntax).

You can use the DEGREES function to convert radians to degrees. You can use the RADIANS function to convert degrees to radians.


The following example shows the effect of ATAN:

SELECT {fn ATAN(0.52)} AS ArcTangent 
Copy code to clipboard

returns 0.47951929199...

See Also