# scipy.special.gdtrc#

scipy.special.gdtrc(a, b, x, out=None) = <ufunc 'gdtrc'>#

Gamma distribution survival function.

Integral from x to infinity of the gamma probability density function,

$F = \int_x^\infty \frac{a^b}{\Gamma(b)} t^{b-1} e^{-at}\,dt,$

where $$\Gamma$$ is the gamma function.

Parameters
aarray_like

The rate parameter of the gamma distribution, sometimes denoted $$\beta$$ (float). It is also the reciprocal of the scale parameter $$\theta$$.

barray_like

The shape parameter of the gamma distribution, sometimes denoted $$\alpha$$ (float).

xarray_like

The quantile (lower limit of integration; float).

outndarray, optional

Optional output array for the function values

Returns
Fscalar or ndarray

The survival function of the gamma distribution with parameters a and b evaluated at x.

Notes

The evaluation is carried out using the relation to the incomplete gamma integral (regularized gamma function).

Wrapper for the Cephes [1] routine gdtrc.

References

1

Cephes Mathematical Functions Library, http://www.netlib.org/cephes/