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HP-UX Reference > T
tgamma(3M)Itanium(R)-based System OnlyHP-UX 11i Version 2: December 2007 Update |
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NAMEtgamma(), tgammaf(), tgammal(), tgammaw(), tgammaq() — true gamma functions SYNOPSIS#include <math.h> double tgamma(double x); float tgammaf(float x); long double tgammal(long double x); extended tgammaw(extended x); quad tgammaq(quad x); DESCRIPTIONThe tgamma() function computes the true gamma function of x. In contrast, the lgamma(), lgamma_r(), and gamma() functions compute the log of gamma. tgammaf() is a float version of tgamma(); it takes a float argument and returns a float result. tgammal() is a long double version of tgamma(); it takes a long double argument and returns a long double result. tgammaw() is an extended version of tgamma(); it takes an extended argument and returns an extended result. tgammaq() is equivalent to tgammal() on HP-UX systems. USAGETo use these functions compile either with the default -Ae option or with the -Aa and -D_HPUX_SOURCE options. To use tgammaw() or tgammaq(), compile also with the -fpwidetypes option. To use any of these functions, make sure your program includes <math.h>, and link in the math library by specifying -lm on the compiler or linker command line. For more information, see the HP-UX Floating-Point Guide. RETURN VALUEIf x equals ±0, tgamma() returns ±INFINITY, and raises the divide-by-zero exception. If x is a negative integer, tgamma() returns a NaN and raises the invalid exception. If x equals -INFINITY, tgamma() returns a NaN and raises the invalid exception. If x equals +INFINITY, tgamma() returns +INFINITY. If x is NaN, tgamma() returns NaN. tgamma() returns infinity (equal to HUGE_VAL) in lieu of a value whose magnitude is too large, and raises the overflow and inexact exceptions. tgamma() raises the inexact exception whenever a rounded result does not equal the mathematical result. |
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