tgamma(3M)						  Mathematical Library Functions						tgamma(3M)

NAME

       tgamma, tgammaf, tgammal - compute gamma function

SYNOPSIS

       c99 [ flag... ] file... -lm [ library... ]
       #include <math.h>

       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 error occurs 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.

		       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 call feclearexcept(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 attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       feclearexcept(3M), fetestexcept(3M), lgamma(3M), math.h(3HEAD), attributes(5), standards(5)

SunOS 5.11							    12 Jul 2006 							tgamma(3M)