Mathematical Library Functions tgamma(3M)
NAME
tgamma, tgammaf, tgammal - compute gamma function
SYNOPSIS
c99 [ flag... ] file... -lm [ library... ]
#include
double tgamma(double x); float tgammaf(float x);long double tgammal(long double x);
DESCRIPTION
These functions compute the gamma() function of x.RETURN VALUES
Upon successful completion, these functions return gamma(x). If x is a negative integer, a domain error occurs and a NaN is returned. If the correct value would cause overflow, a range erroroccurs and tgamma(), tgammaf(), and tgammal() return the
value of the macro +_HUGE_VAL, +_HUGE_VALF, or +_HUGE_VALL,
respectively. If x is NaN, a NaN is returned.If x is +_Inf, x is returned.
If x is +_0, a pole error occurs and tgamma(), tgammaf(), and
tgammal() return +_HUGE_VAL, +_HUGE_VALF, and +_HUGE_VALL,
respectively. If x is +Inf, a domain error occurs and a NaN is returned.ERRORS
These functions will fail if: Domain Error The value of x is a negative integer or x is-Inf.
SunOS 5.11 Last change: 12 Jul 2006 1
Mathematical Library Functions tgamma(3M)If the integer expression (math_errhandling
& MATH_ERREXCEPT) is non-zero, then the
invalid floating-point exception is raised.
Pole Error The value of x is zero.If the integer expression (math_errhandling
& MATH_ERREXCEPT) is non-zero, then the
divide-by-zero floating-point exception is
raised. Range Error The value overflows.If the integer expression (math_errhandling
& MATH_ERREXCEPT) is non-zero, then the
overflow floating-point exception is raised.
USAGE
An application wanting to check for exceptions should callfeclearexcept(FE_ALL_EXCEPT) before calling these functions.
On return, if fetestexcept(FE_INVALID | FE_DIVBYZERO |
FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an exception has
been raised. An application should either examine the return value or check the floating point exception flags to detect exceptions.ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Interface Stability | Committed ||_____________________________|_____________________________|
| MT-Level | MT-Safe |
|_____________________________|_____________________________|
| Standard | See standards(5). ||_____________________________|_____________________________|
SEE ALSO
feclearexcept(3M), fetestexcept(3M), lgamma(3M), math.h(3HEAD), attributes(5), standards(5)SunOS 5.11 Last change: 12 Jul 2006 2