libdevice User's Guide :: CUDA Toolkit Documentation

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libdevice User's Guide (PDF) - v6.0 (older) - Last updated February 13, 2014 - Send Feedback -

3.201. __nv_lgamma

Prototype:

double @__nv_lgamma(double %x)

Description:

Calculate the natural logarithm of the absolute value of the gamma function of the input argument x, namely the value of $\log_{e} (\int_{0}^{\infty} e^{- t} t^{x - 1} d t)$

Returns:

__nv_lgamma(1) returns +0.
__nv_lgamma(2) returns +0.
__nv_lgamma(x) returns $\pm \infty$ if the correctly calculated value is outside the double floating point range.
__nv_lgamma(x) returns $+ \infty$ if x $\leq$ 0.
__nv_lgamma( $- \infty$ ) returns $- \infty$ .
__nv_lgamma( $+ \infty$ ) returns $+ \infty$ .

Note:

For accuracy information for this function see the CUDA C Programming Guide, Appendix D.1, Table 7.

Library Availability:

Compute 2.0: Yes

Compute 3.0: Yes

Compute 3.5: Yes