# Zero Inflated Poisson Log-Lik

**URL:** <https://discourse.pymc.io/t/zero-inflated-poisson-log-lik/2664>\
**Category:** Questions\
**Created:** [February 6, 2019, 12:49am UTC](https://discourse.pymc.io/t/zero-inflated-poisson-log-lik/2664 "2019-02-06T00:49:44Z")\
**Posts on this page:** 1\
**Showing post:** 3

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**Author:** ![Brian](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.pymc.io/brian/32/7088_2.png) [@Brian](https://discourse.pymc.io/u/Brian)\
**Post date:** [February 6, 2019, 1:46pm UTC](https://discourse.pymc.io/t/zero-inflated-poisson-log-lik/2664/3 "2019-02-06T13:46:47Z")

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Thank you so much! I appreciate it!

One issue I also found was confusion on my side in regards to what ‘p’ represents. I was under the impression it was the probability of zero, but it seems as parameterized I need to pass in (1-p) to match what I did with the built in function (to match the rethinking statistics book) as this set-up in pymc3 appears to assume p is the probability of not zero?

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