pymc.HurdleGamma#
- class pymc.HurdleGamma(name, psi, alpha=None, beta=None, mu=None, sigma=None, **kwargs)[source]#
Hurdle Gamma log-likelihood.
\[\begin{split}f(x \mid \psi, \alpha, \beta) = \left\{ \begin{array}{l} (1 - \psi) \ \text{if } x = 0 \\ \psi \frac{\text{GammaPDF}(x \mid \alpha, \beta))} {1 - \text{GammaCDF}(\epsilon \mid \alpha, \beta)} \ \text{if } x=1,2,3,\ldots \end{array} \right.\end{split}\]where \(\epsilon\) is the machine precision.
- Parameters:
- psitensor_like of
float Expected proportion of Gamma draws (0 < psi < 1)
- alphatensor_like of
float, optional Shape parameter (alpha > 0).
- betatensor_like of
float, optional Rate parameter (beta > 0).
- mutensor_like of
float, optional Alternative shape parameter (mu > 0).
- sigmatensor_like of
float, optional Alternative scale parameter (sigma > 0).
- psitensor_like of
Methods
HurdleGamma.dist(psi[, alpha, beta, mu, sigma])