Guardian Native C Library Calls Reference Manual (G06.28+, H06.04+)

Guardian Native C Library Calls (a - e) asinh(3)
NAME
asinh - Computes the inverse hyperbolic sine function
LIBRARY
G-series native Guardian processes: $SYSTEM.SYSnn.ZCRESRL
G-series native OSS processes: /G/system/sysnn/zcresrl
H-series native Guardian processes: $SYSTEM.ZDLLnnn.ZCREDLL
H-series OSS processes: /G/system/zdllnnn/zcredll
SYNOPSIS
#include <math.h>
double asinh(
double x);
PARAMETERS
x Is the value for which the inverse hyperbolic sine function is to be computed.
DESCRIPTION
The asinh( ) function computes the inverse hyperbolic sine of x.
The asinh( ) function can be called only by native processes.
NOTES
This function supports both IEEE Std 754-1985 floating-point and Tandem floating-point values.
IEEE values can include NaN and infinity, and the sign of 0.0 (zero) can be either positive or
negative. Refer to the fp_class(3) reference page for a description of IEEE value classes.
Guardian functions are available to convert between floating-point formats. Refer to the Guar-
dian Programmer’s Guide for a discussion of floating-point conversions.
RETURN VALUES
The asinh( ) function returns the inverse hyperbolic sine of the x parameter.
For IEEE floating-point values, when the value of x is NaN, the asinh( ) function returns NaN. If
the value of x is positive infinity, the asinh( ) function returns positive infinity. If the value of x is
negative infinity, the asinh() function returns negative infinity.
ERRORS
The asinh( ) function does not set errno.
RELATED INFORMATION
Functions: asin(3), acos(3), acosh(3), atan(3), atan2(3), atanh(3), fp_class(3), isnan(3).
STANDARDS CONFORMANCE
The XPG4 Version 2 specification leaves some features to the implementing vendor to define.
The following features are affected in the HP implementation:
• When used for IEEE floating-point values, this function does not set errno to [EDOM]
when the value of x is NaN.
• When used for Tandem floating-point values, this function does not return the value NaN
when an invalid parameter is passed.
527192-005 Hewlett-Packard Company 1−13