# Slow Sampling in Virtual Environment

**URL:** <https://discourse.pymc.io/t/slow-sampling-in-virtual-environment/12084>\
**Category:** Questions\
**Created:** [May 8, 2023, 9:39am UTC](https://discourse.pymc.io/t/slow-sampling-in-virtual-environment/12084 "2023-05-08T09:39:18Z")\
**Posts on this page:** 1\
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**Author:** ![jessegrabowski](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.pymc.io/jessegrabowski/32/5010_2.png) [@jessegrabowski](https://discourse.pymc.io/u/jessegrabowski)\
**Post date:** [May 8, 2023, 8:09pm UTC](https://discourse.pymc.io/t/slow-sampling-in-virtual-environment/12084/2 "2023-05-08T20:09:19Z")

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When I make fake data and run your model as written, it samples extremely fast.

I would check the shapes of all your variables to make sure they are what you expect you are. `pm.model_to_graphviz` is convenient for doing this. If that’s not the problem, your priors might be too narrow. Standardizing the input data (`df` in your model) often helps as well (see [here](https://discourse.pymc.io/t/bambi-much-faster-then-my-pymc-implementation-of-negative-binomial-regression/10438) for a discussion on scaling/centering and priors)

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