tgamma

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tgamma
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Defined in header <math.h>
float       tgammaf( float arg );
(since C99)
double      tgamma( double arg );
(since C99)
long double tgammal( long double arg );
(since C99)

Computes the gamma function of arg.

Contents

[edit] Parameters

arg - floating point value

[edit] Return value

The value of the gamma function of arg, that is
0
targ-1
e-t dt
.

If arg is a natural number, tgamma(arg) is the factorial of arg-1.

[edit] Exceptions

If arg is negative, domain error may occur and FE_INVALID may be raised.

If arg is zero, pole error may occur and FE_DIVBYZERO may be raised.

If arg is too large, range error may occur and FE_OVERFLOW may be raised.

If arg is too small, range error may occur and FE_UNDERFLOW may be raised.

[edit] Notes

Many implementations calculate the exact integer-domain factorial if the argument is a sufficiently small integer.

[edit] Example

[edit] See also

(C99)
natural logarithm of the gamma function
(function)
C++ documentation for tgamma

[edit] External links

Weisstein, Eric W. "Gamma Function." From MathWorld--A Wolfram Web Resource.