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# tgamma

From cppreference.com
< c‎ | numeric‎ | math

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`.

### [edit] Parameters

arg | - | floating point value

### [edit] Return value

The value of the gamma function of `arg`, that is ∫∞
0 t arg-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

| This section is incomplete Reason: no example

### [edit] See also

lgamma (C99) | natural logarithm of the gamma function (function) [edit]
C++ documentation for tgamma

### [edit] External links

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

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