apop_yule.c File Reference

Variables

The Yule distribution. A special case of the Waring.

The Yule distribution

The special case of Waring where $\alpha = 0.$

apop_yule.estimate() is an MLE, so feed it appropriate apop_mle_settings.

$Y(x, b) = (b-1) \gamma(b) \gamma(k) / \gamma(k+b)$

$\ln Y(x, b) = \ln(b-1) + ln\gamma(b) + \ln\gamma(k) - \ln\gamma(k+b)$

$d\ln Y/db = 1/(b-1) + \psi(b) - \psi(k+b)$

To specify that you have frequency or ranking data, use

Apop_settings_add_group(your_model, apop_rank, NULL);

Todo:: I'm pretty sure Wikipedia's specification of the Yule is wrong; I should check and fix when I have references on hand.