CrossWorks for ARM User Guide

Fast math librarybehaviorIEC 60559 mathlibrary behaviorPortabilityIf x = y = 0, errno (page 247) is set to EDOM and atan2f returns HUGE_VALF.atan2f(x, NaN) is NaNatan2f(NaN, x) is NaNatan2f(0, +(anything but NaN)) is 0atan2f(0, -(anything but NaN)) is ?atan2f((anything but 0 and NaN), 0) is ?/2atan2f((anything but Infinity and NaN), +Infinity) is 0atan2f((anything but Infinity and NaN), -Infinity) is ?atan2f(Infinity, +Infinity) is ?/4atan2f(Infinity, -Infinity) is 3?/4atan2f(Infinity, (anything but 0, NaN, and Infinity)) is ?/2atan2f conforms to ISO/IEC 9899:1990 (C90) and ISO/IEC 9899:1999 (C99).See Also atanf (page 259)atanfSynopsisDescriptionPortability#include float atanf(float x);atanf returns the principal value, in radians, of the inverse circular tangent of x. Theprincipal value lies in the interval [-¾?, +¾?] radians.atanf conforms to ISO/IEC 9899:1990 (C90) and ISO/IEC 9899:1999 (C99).atanhSynopsis#include double atanh(double x)Description atanh returns the inverse hyperbolic tangent of x.Fast math libraryIEC 60559 mathlibrary behaviorPortabilityIf |x| ? 1, errno is set to EDOM and atanh returns HUGE_VAL.If |x| > 1 atanh returns NaN with signal.If x is NaN, atanh returns that NaN with no signal.If x is 1, atanh returns Infinity with signal.If x is -1, atanh returns -Infinity with signal.atanh conforms to ISO/IEC 9899:1999 (C99).Chapter 28 - Mathematics259