# version agnostic

**URL:** https://discourse.pymc.io/c/questions/version-agnostic/20.md

[Latest](https://discourse.pymc.io/latest.md) · [Categories](https://discourse.pymc.io/categories.md) · [Tags](https://discourse.pymc.io/tags.md)

---

## [About the version agnostic category](https://discourse.pymc.io/t/about-the-version-agnostic-category/8935)

<div class="topic-metadata">

**Author:** [@OriolAbril](https://discourse.pymc.io/u/OriolAbril)\
**Replies:** 0

</div>

---

## [Bambi, Count data and thresholds](https://discourse.pymc.io/t/bambi-count-data-and-thresholds/17926)

<div class="topic-metadata">

**Author:** [@Pegguins](https://discourse.pymc.io/u/Pegguins)\
**Replies:** 9\
**Last updated:** [September 24, 2026, 9:28am UTC](https://discourse.pymc.io/t/bambi-count-data-and-thresholds/17926 "2026-09-24T09:28:55Z")

</div>

Hi. I’ve been tinkering away with some Bambi model development. I’m looking at some attendence data. We’re interested in modelling the number of times people attend, but also whether people are over a specific threshold…

---

## [Guide to Bayesian Viz?](https://discourse.pymc.io/t/guide-to-bayesian-viz/15909)

<div class="topic-metadata">

**Author:** [@rsenne](https://discourse.pymc.io/u/rsenne)\
**Replies:** 6\
**Last updated:** [June 24, 2026, 8:45pm UTC](https://discourse.pymc.io/t/guide-to-bayesian-viz/15909 "2026-06-24T20:45:57Z")

</div>

I was curious if anyone has good resources for Bayesian visualization? I’m doing some modelling for an academic paper and am using Hierarchical GLMs. I’m relatively new to using primarily Bayesian methods, but I’m turnin…

---

## [Timeseries binary-decision problem](https://discourse.pymc.io/t/timeseries-binary-decision-problem/17441)

<div class="topic-metadata">

**Author:** [@Tester](https://discourse.pymc.io/u/Tester)\
**Replies:** 9\
**Last updated:** [April 9, 2026, 7:19pm UTC](https://discourse.pymc.io/t/timeseries-binary-decision-problem/17441 "2026-04-09T19:19:30Z")

</div>

I have data from an experiment in which subjects repeatedly completed a specific task that required a forced binary decision (option A vs. B). I only observe this decision at the end of each recording. As predictors/IVs,…

---

## [Can't get predictions from Bambi. Encountering \`ValueError: different number of dimensions on data and dims: 0 vs 2\`](https://discourse.pymc.io/t/cant-get-predictions-from-bambi-encountering-valueerror-different-number-of-dimensions-on-data-and-dims-0-vs-2/17684)

<div class="topic-metadata">

**Author:** [@nickeubank](https://discourse.pymc.io/u/nickeubank)\
**Replies:** 5\
**Last updated:** [April 3, 2026, 2:13am UTC](https://discourse.pymc.io/t/cant-get-predictions-from-bambi-encountering-valueerror-different-number-of-dimensions-on-data-and-dims-0-vs-2/17684 "2026-04-03T02:13:20Z")

</div>

(apologies this is a bit of a cross post — I posted as a bambi github issue first before it occurred to me that pymc may have a more populated forum that might also be a better place since I’m not sure if this is user er…

---

## [Consider adding numerically stable \`logccdf\` (log survival function) to Exponential, Weibull and other distro](https://discourse.pymc.io/t/consider-adding-numerically-stable-logccdf-log-survival-function-to-exponential-weibull-and-other-distro/17603)

<div class="topic-metadata">

**Author:** [@vybhav72954](https://discourse.pymc.io/u/vybhav72954)\
**Replies:** 18\
**Last updated:** [March 18, 2026, 1:14pm UTC](https://discourse.pymc.io/t/consider-adding-numerically-stable-logccdf-log-survival-function-to-exponential-weibull-and-other-distro/17603 "2026-03-18T13:14:35Z")

</div>

Hi everyone, While going through the codebase, I noticed that logccdf (the log complementary CDF, equivalent to the log survival function \\log S(t) = \\log(1 - F(t))) has a numerically stable registered implementation fo…

---

## [Recommendations for implementing differentiable sampling (reparameterization trick) in PyTensor?](https://discourse.pymc.io/t/recommendations-for-implementing-differentiable-sampling-reparameterization-trick-in-pytensor/17469)

<div class="topic-metadata">

**Author:** [@flob](https://discourse.pymc.io/u/flob)\
**Replies:** 3\
**Last updated:** [December 7, 2025, 3:13pm UTC](https://discourse.pymc.io/t/recommendations-for-implementing-differentiable-sampling-reparameterization-trick-in-pytensor/17469 "2025-12-07T15:13:15Z")

</div>

Hi everyone, I am new to PyTensor/ PyMC, so apologies in advance if this is a basic question. Background: I am trying to port a simulation-based optimization workflow from TensorFlow to PyTensor. The Problem: I need t…

---

## [How to find conditional distribution of missing values?](https://discourse.pymc.io/t/how-to-find-conditional-distribution-of-missing-values/17443)

<div class="topic-metadata">

**Author:** [@messier12](https://discourse.pymc.io/u/messier12)\
**Replies:** 7\
**Last updated:** [November 21, 2025, 4:11am UTC](https://discourse.pymc.io/t/how-to-find-conditional-distribution-of-missing-values/17443 "2025-11-21T04:11:55Z")

</div>

Hi, I’m new to bayesian statistics and pymc. Say I have N variable correlated according to a MVN distribution. I have train dataset that I can use to find the posterior distribution of the MVN. Then I have new data whic…

---

## [Some questions on GPU based sampling](https://discourse.pymc.io/t/some-questions-on-gpu-based-sampling/16583)

<div class="topic-metadata">

**Author:** [@bayesian\_padawan](https://discourse.pymc.io/u/bayesian_padawan)\
**Replies:** 10\
**Last updated:** [November 7, 2025, 6:21pm UTC](https://discourse.pymc.io/t/some-questions-on-gpu-based-sampling/16583 "2025-11-07T18:21:58Z")

</div>

Hi all, up to now, I was using only CPU based sampling and was somehow hesitant to set up an environment which might support GPU based sampling. I found the article Set up JAX sampling with GPUs in PyMC which gives som…

---

## [Speed UP Bambi Fitting](https://discourse.pymc.io/t/speed-up-bambi-fitting/17419)

<div class="topic-metadata">

**Author:** [@Ahmed\_Dawoud](https://discourse.pymc.io/u/Ahmed_Dawoud)\
**Replies:** 4\
**Last updated:** [November 1, 2025, 2:15pm UTC](https://discourse.pymc.io/t/speed-up-bambi-fitting/17419 "2025-11-01T14:15:53Z")

</div>

Hi Bambi Folks, Thanks for making Bayesian inference more accessible! I’m facing an issue where the compute time grows exponentially with data size. I’m running on a Colab Pro plan — does Bambi support GPU acceleration?…

---

## [Getting prior when prior predictive results are given](https://discourse.pymc.io/t/getting-prior-when-prior-predictive-results-are-given/17413)

<div class="topic-metadata">

**Author:** [@HVEC-lab](https://discourse.pymc.io/u/HVEC-lab)\
**Replies:** 3\
**Last updated:** [November 1, 2025, 4:05am UTC](https://discourse.pymc.io/t/getting-prior-when-prior-predictive-results-are-given/17413 "2025-11-01T04:05:28Z")

</div>

I have a problem where expert input is given which can be viewed as reflecting the prior-predictive distribution. I need to transform this information into an estimate of the prior. Is this process facilitated in some wa…

---

## [Regression with censored input data](https://discourse.pymc.io/t/regression-with-censored-input-data/17406)

<div class="topic-metadata">

**Author:** [@leomein](https://discourse.pymc.io/u/leomein)\
**Replies:** 2\
**Last updated:** [October 28, 2025, 3:53pm UTC](https://discourse.pymc.io/t/regression-with-censored-input-data/17406 "2025-10-28T15:53:05Z")

</div>

Hi all, I have a situation where my response variable but also one of the independent variables are censored. I’ve found a lot online on the topic of a censored response variable but not much on the case of censored inp…

---

## [Overflow issues with PyMC-BART](https://discourse.pymc.io/t/overflow-issues-with-pymc-bart/17202)

<div class="topic-metadata">

**Author:** [@krishasenbein](https://discourse.pymc.io/u/krishasenbein)\
**Replies:** 10\
**Last updated:** [October 22, 2025, 3:37pm UTC](https://discourse.pymc.io/t/overflow-issues-with-pymc-bart/17202 "2025-10-22T15:37:02Z")

</div>

Hi y’all! Long time lurker, first time poster. I recently read @aloctavodia 's book on Bayesian Analysis with Python and enthusiastically fitted a Gamma BART model last Friday. Today when I came back to the model it won’…

---

## [Ordinal regression with non-normally distributed response variable](https://discourse.pymc.io/t/ordinal-regression-with-non-normally-distributed-response-variable/17356)

<div class="topic-metadata">

**Author:** [@leomein](https://discourse.pymc.io/u/leomein)\
**Replies:** 6\
**Last updated:** [October 2, 2025, 6:01pm UTC](https://discourse.pymc.io/t/ordinal-regression-with-non-normally-distributed-response-variable/17356 "2025-10-02T18:01:51Z")

</div>

Hi! I just read through Regression Models with Ordered Categorical Outcomes — PyMC example gallery and am thinking about applying such a model to my data (currently using logistic regression because the response can be …

---

## [Rationale & interpretation of \`plot\_direct\_contribution\_curves\`](https://discourse.pymc.io/t/rationale-interpretation-of-plot-direct-contribution-curves/16192)

<div class="topic-metadata">

**Author:** [@Jonas](https://discourse.pymc.io/u/Jonas)\
**Replies:** 2\
**Last updated:** [September 14, 2025, 12:01pm UTC](https://discourse.pymc.io/t/rationale-interpretation-of-plot-direct-contribution-curves/16192 "2025-09-14T12:01:48Z")

</div>

Hi, I have wondered about the rationale behind the direct contribution plot in general and the connection to fitted saturation curves in general. My understanding is that the scatter plot created by plot\_direct\_contrib…

---

## [Working with Multi-index Coords](https://discourse.pymc.io/t/working-with-multi-index-coords/16113)

<div class="topic-metadata">

**Author:** [@dreycenfoiles](https://discourse.pymc.io/u/dreycenfoiles)\
**Replies:** 12\
**Last updated:** [September 8, 2025, 8:48pm UTC](https://discourse.pymc.io/t/working-with-multi-index-coords/16113 "2025-09-08T20:48:36Z")

</div>

Hello, I’ve got an ArviZ and PyMC combo question. I’ve been working with some uneven, long, data that I’m managing with multi-indexes. This workflow works pretty well except PyMC models can’t accept multi-indexes in the…

---

## [Dealing with large unaffected cohort in parametric survival analysis](https://discourse.pymc.io/t/dealing-with-large-unaffected-cohort-in-parametric-survival-analysis/17315)

<div class="topic-metadata">

**Author:** [@ddg.palmer](https://discourse.pymc.io/u/ddg.palmer)\
**Replies:** 5\
**Last updated:** [September 5, 2025, 12:42am UTC](https://discourse.pymc.io/t/dealing-with-large-unaffected-cohort-in-parametric-survival-analysis/17315 "2025-09-05T00:42:42Z")

</div>

Hi there. I’m looking for some advice in better specifying my model, since it’s fitting to the data correctly, but not in the way that I want. I have a project fitting multiple survival models to epidemiological data, w…

---

## [Use linear programming in a model](https://discourse.pymc.io/t/use-linear-programming-in-a-model/17307)

<div class="topic-metadata">

**Author:** [@threepwood](https://discourse.pymc.io/u/threepwood)\
**Replies:** 4\
**Last updated:** [September 1, 2025, 4:50pm UTC](https://discourse.pymc.io/t/use-linear-programming-in-a-model/17307 "2025-09-01T16:50:04Z")

</div>

I realized that a fairly elaborate combinatorial computation involved in my model can be reduced to a linear program, and then solved very efficiently for particular parameter values. I was wondering if there is a way to…

---

## [Seeking Advice on my Model](https://discourse.pymc.io/t/seeking-advice-on-my-model/17245)

<div class="topic-metadata">

**Author:** [@steeeeevo](https://discourse.pymc.io/u/steeeeevo)\
**Replies:** 4\
**Last updated:** [August 12, 2025, 5:11pm UTC](https://discourse.pymc.io/t/seeking-advice-on-my-model/17245 "2025-08-12T17:11:39Z")

</div>

Hello and thank you for reading this. I’m looking for some general advice and some advice regarding my specific model. Any help you could provide would be very appreciated! Assumptions: 2 types of Lego kits We know…

---

## [CausalPy - Intuition behind calculation of causal impact and treatment time inputs](https://discourse.pymc.io/t/causalpy-intuition-behind-calculation-of-causal-impact-and-treatment-time-inputs/17069)

<div class="topic-metadata">

**Author:** [@ykarle](https://discourse.pymc.io/u/ykarle)\
**Replies:** 8\
**Last updated:** [July 29, 2025, 11:59am UTC](https://discourse.pymc.io/t/causalpy-intuition-behind-calculation-of-causal-impact-and-treatment-time-inputs/17069 "2025-07-29T11:59:21Z")

</div>

Was following the below CausalPy tutorial for Interrupted Time Series and using it for a simple pre-post comparison. Pre-world consists of the old world which had a old model controlling the outputs and post-world cons…

---

## [More elegant way to construct random effects model](https://discourse.pymc.io/t/more-elegant-way-to-construct-random-effects-model/17214)

<div class="topic-metadata">

**Author:** [@79885yhnert67h](https://discourse.pymc.io/u/79885yhnert67h)\
**Replies:** 1\
**Last updated:** [July 24, 2025, 2:48pm UTC](https://discourse.pymc.io/t/more-elegant-way-to-construct-random-effects-model/17214 "2025-07-24T14:48:02Z")

</div>

Hello, I’m new to PyMC (and Bayesian regression modeling in general) so it’s likely this question is covered in the docs, but I’m not sure exactly what keyword I need to search for. Basically, I am trying to sauce up a …

---

## [How to save trace in between sampling and then resume sampling later on?](https://discourse.pymc.io/t/how-to-save-trace-in-between-sampling-and-then-resume-sampling-later-on/16785)

<div class="topic-metadata">

**Author:** [@Aravind27](https://discourse.pymc.io/u/Aravind27)\
**Replies:** 2\
**Last updated:** [July 10, 2025, 4:36am UTC](https://discourse.pymc.io/t/how-to-save-trace-in-between-sampling-and-then-resume-sampling-later-on/16785 "2025-07-10T04:36:41Z")

</div>

Hello everyone, I would like to save the trace every n samples or so. Is there a way to do this in pymc? Specifically, I would like to do something like the following pseudo code: with pm.Model() as model: ## priors…

---

## [Using impressions data for MMM with PyMC Marketing](https://discourse.pymc.io/t/using-impressions-data-for-mmm-with-pymc-marketing/17063)

<div class="topic-metadata">

**Author:** [@Shagun\_Kala](https://discourse.pymc.io/u/Shagun_Kala)\
**Replies:** 2\
**Last updated:** [July 6, 2025, 12:09pm UTC](https://discourse.pymc.io/t/using-impressions-data-for-mmm-with-pymc-marketing/17063 "2025-07-06T12:09:09Z")

</div>

Hi everyone, In my current project, after careful evaluation, we’ve decided to train our MMM (Marketing Mix Modeling) using impressions data instead of spend data. However, I’ve noticed that the PyMC Marketing framework…

---

## [Newton raphson solver using pt.scan](https://discourse.pymc.io/t/newton-raphson-solver-using-pt-scan/17081)

<div class="topic-metadata">

**Author:** [@Akash\_Dasgupta](https://discourse.pymc.io/u/Akash_Dasgupta)\
**Replies:** 3\
**Last updated:** [June 11, 2025, 4:37am UTC](https://discourse.pymc.io/t/newton-raphson-solver-using-pt-scan/17081 "2025-06-11T04:37:27Z")

</div>

Hi all! I am new to using this library and was wondering if I could get a little bit of help. I am trying to solve a differential equatio using Newton Raphson. I’m attaching the simplified version below: def newton\_raph…

---

## [HSGP + Intrinsic Coregionalization Model, is this possible?](https://discourse.pymc.io/t/hsgp-intrinsic-coregionalization-model-is-this-possible/16720)

<div class="topic-metadata">

**Author:** [@Cricket4444](https://discourse.pymc.io/u/Cricket4444)\
**Replies:** 4\
**Last updated:** [May 28, 2025, 2:30pm UTC](https://discourse.pymc.io/t/hsgp-intrinsic-coregionalization-model-is-this-possible/16720 "2025-05-28T14:30:08Z")

</div>

I’m trying to follow this example: Multi-output Gaussian Processes: Coregionalization models using Hamadard product — PyMC example gallery especially I’m interested in predicting the outcomes within temporal gaps for so…

---

## [Data with different levels of aggregation](https://discourse.pymc.io/t/data-with-different-levels-of-aggregation/16993)

<div class="topic-metadata">

**Author:** [@leomein](https://discourse.pymc.io/u/leomein)\
**Replies:** 11\
**Last updated:** [May 22, 2025, 2:19pm UTC](https://discourse.pymc.io/t/data-with-different-levels-of-aggregation/16993 "2025-05-22T14:19:02Z")

</div>

Hi all, I want to fit a dataset that contains information on both the individual and the group level. The (binary) outcome and some input variables are on the individual level, some other input variables (including the …

---

## [Saving and loading GP model using trace data gives wrong output shape](https://discourse.pymc.io/t/saving-and-loading-gp-model-using-trace-data-gives-wrong-output-shape/17022)

<div class="topic-metadata">

**Author:** [@cola](https://discourse.pymc.io/u/cola)\
**Replies:** 0\
**Last updated:** [May 20, 2025, 3:48pm UTC](https://discourse.pymc.io/t/saving-and-loading-gp-model-using-trace-data-gives-wrong-output-shape/17022 "2025-05-20T15:48:22Z")

</div>

Hello, I am trying to save and load the trace from a gp model to use the model for production. Here is my trial, everything seems to work except that I expect the gp.predict to give me one output for each Xnew input, ho…

---

## [Bayesian test of independence of discrete events A and B](https://discourse.pymc.io/t/bayesian-test-of-independence-of-discrete-events-a-and-b/16992)

<div class="topic-metadata">

**Author:** [@cowirihy](https://discourse.pymc.io/u/cowirihy)\
**Replies:** 6\
**Last updated:** [May 20, 2025, 2:47pm UTC](https://discourse.pymc.io/t/bayesian-test-of-independence-of-discrete-events-a-and-b/16992 "2025-05-20T14:47:49Z")

</div>

I’m looking to implement a Bayesian test of whether discrete events / outcomes A and B are independent or not, as an alternative to the frequentist chi-squared test (or similar). I have paired count data arranged in the…

---

## [Complex hierarchy in bambi, is this possible?](https://discourse.pymc.io/t/complex-hierarchy-in-bambi-is-this-possible/16996)

<div class="topic-metadata">

**Author:** [@Cricket4444](https://discourse.pymc.io/u/Cricket4444)\
**Replies:** 2\
**Last updated:** [May 14, 2025, 6:39pm UTC](https://discourse.pymc.io/t/complex-hierarchy-in-bambi-is-this-possible/16996 "2025-05-14T18:39:55Z")

</div>

I’m using a GLM to model some treatment effects, in the simplest form it looks like this: mu = 1 + treatment:individual however my subjects are categorized in groups, I want to build a hierarchy, so that the individual…

---

## [What is the correct way to validate a customer being alive in a BTYD model?](https://discourse.pymc.io/t/what-is-the-correct-way-to-validate-a-customer-being-alive-in-a-btyd-model/16930)

<div class="topic-metadata">

**Author:** [@jeremyloscheider](https://discourse.pymc.io/u/jeremyloscheider)\
**Replies:** 2\
**Last updated:** [April 29, 2025, 6:48pm UTC](https://discourse.pymc.io/t/what-is-the-correct-way-to-validate-a-customer-being-alive-in-a-btyd-model/16930 "2025-04-29T18:48:01Z")

</div>

@pymc-bot I’m using BetaGeoNBD, ParetoNBD and Modified BetaGeoNBD models to predict the likelihood of a customer being alive at some future week n for a range, say n in\[4,8,13,17,22,26\]. The models are trained on data …

[Next page](https://discourse.pymc.io/c/questions/version-agnostic/20.md?page=1)