Open System Services Library Calls Reference Manual (G06.29+, H06.08+, J06.03+)

OSS Library Calls (t - v) tgammaf(3)
NAME
tgammaf - Computes the true gamma 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 tgammaf(
float x);
PARAMETERS
x Specifies a positive float value.
DESCRIPTION
The tgammaf() function is a float version of the tgamma() function; it takes a float argument
and returns a float result.
The tgammaf() function computes the true gamma function of x. In contrast, the lgammaf( )
function and the gamma( ) function compute the logarithm of gamma.
NOTES
This function is implemented only for the IEEE_float floating-point option. Applications using
this function cannot be compiled if the specified floating-point option is Tandem_float.
RETURN VALUES
Upon successful completion, the tgammaf( ) function returns the true gamma of x.
If the value of x is a negative integer, NaN is returned and errno is set to [EDOM].
If the value of x is NaN, NaN is returned.
If the value of x is positive infinity, x is returned.
If the value of x is negative infinity, NaN is returned and errno is set to [EDOM].
If the value of x is positive or negative zero, HUGE_VALF is returned and errno is set to
[ERANGE].
If the result would cause overflow, +HUGE_VALF or -HUGE_VALF (with the same sign as the
correct value of the function) is returned and errno is set to [ERANGE].
ERRORS
If any of the following conditions occurs, the tgammaf( ) function sets errno to the correspond-
ing value:
[EDOM] The value of x is a negative integer or negative infinity.
[ERANGE] The value to be returned is positive or negative zero or would cause overflow.
RELATED INFORMATION
Functions: exp(3), lgamma(3), log(3), tgamma(3), tgammal(3).
Files: math(4).
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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