Guardian Native C Library Calls Reference Manual (G06.29+, H06.08+, J06.03+)

erff(3) Guardian Native C Library Calls Reference Manual
NAME
erff - Computes the error function for a float value
LIBRARY
H-series and J-series native Guardian processes: $SYSTEM.ZDLLnnn.ZCREDLL
32-bit H-series and J-series OSS processes: /G/system/zdllnnn/zcredll
64-bit H-series and J-series OSS processes: /G/system/zdllnnn/ycredll
SYNOPSIS
#include <math.h>
float erff(
float x);
PARAMETERS
x Specifies the float value for which the error function is to be computed.
DESCRIPTION
The erff() function is a float version of the erf() function; it takes a float argument and returns a
float result.
The erff() function computes the error function of x, defined as:
√
π
2
___
0
∫
x
e
−t
2
dt
NOTES
The erff() function can be called only by native processes.
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
Upon successful completion, the erff() function returns the value of the error function.
For IEEE floating-point values, if the value of x is NaN, NaN is returned.
If the correct value would cause underflow, 0.0 (zero) is returned.
ERRORS
No errors are returned. This function does not set errno.
RELATED INFORMATION
Functions: erf(3), erfl(3), erfc(3), exp(3), fp_class(3), isnan(3).
STANDARDS CONFORMANCE
This function conforms to the ISO/IEC 9899:1999 standard.
This function conforms to the IEEE Std 1003.1, 2004 Edition.
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