libdevice User's Guide :: CUDA Toolkit Documentation

3.287. __nv_tgamma

Prototype:

double @__nv_tgamma(double %x)

Description:

Calculate the gamma function of the input argument x, namely the value of $\int_{0}^{\infty} e^{- t} t^{x - 1} d t$ .

Returns:

__nv_tgamma( $\pm 0$ ) returns $\pm \infty$ .
__nv_tgamma(2) returns +0.
__nv_tgamma(x) returns $\pm \infty$ if the correctly calculated value is outside the double floating point range.
__nv_tgamma(x) returns NaN if x < 0.
__nv_tgamma( $- \infty$ ) returns NaN.
__nv_tgamma( $+ \infty$ ) returns $+ \infty$ .

Note:

For accuracy information see the CUDA C++ Programming Guide, Mathematical Functions Appendix, Double-Precision Floating-Point Functions section.

Library Availability:

Compute 2.0: Yes

Compute 3.0: Yes

Compute 3.5: Yes