math:atan

Returns the arc tangent of the argument, the result being in the range -π/2 to +π/2 radians.

atan($arg as xs:double?) ➔ xs:double?

Namespace

http://www.w3.org/2005/xpath-functions/math

Links to W3C specifications

XPath 3.1 Functions and Operators

Notes on the Saxon implementation

Implemented since Saxon 9.3; available whether or not XPath 3.0 is enabled. Saxon also (for compatibility) implements the function math:atan() in namespace http://exslt.org/math.