[quote=“tcapretto, post:2, topic:10858”]

`Thank you for your help.

I installed pymc with: ‘pip install pymc’`

then I imported:

import arviz as az

import bambi as bmb

import matplotlib.pyplot as plt

import numpy as np

import pandas as pd

import seaborn as sns

import pymc as pm

print(“Bambi:”, bmb.**version**)

print(“PyMC:”, pm.**version**)

gives:

Bambi: 0.9.1

PyMC: 4.3.0

then following the Bambi first example from the Bambi documentation:

#
Comparison of two means (T-test):

bambinos.github Comparison of two means (T-test) — Bambi 0.9.1 documentation)

a = np.random.normal(6, 2.5, 160)

b = np.random.normal(8, 2, 120)

df = pd.DataFrame({“Group”: [“a”] * 160 + [“b”] * 120, “Val”: np.hstack([a, b])})

df.sample(10)

model_1 = bmb.Model(“Val ~ Group”, df)

results_1 = model_1.fit()

this still gives:

‘cannot pickle ‘fortran’ object’ error.

If instead I

import pymc3 as pm

print(“Bambi:”, bmb.**version**)

print(“PyMC3:”, pm.**version**)

I get:

Bambi: 0.9.1

PyMC: 3.11.5

and then run the model, I still get the same error.

mayby I am not installing pymc correctly and the two versions are interferring with each other?

I have since gone on to run other models on Bambi successfully, but when I return to this example above from the Bambi website it fails with the aforementioned error.

If I modify the model by setting the intercept to zero it then works!:

model_2 = bmb.Model(“Val ~ 0+Group”, df)

results_2 = model_2.fit()

but why the first model, designated model1(model_1 = bmb.Model(“Val ~ Group”, df)) on the Bambi website fails on my computer I do not know. Comparing two means is a useful model.

Putting this all together I am not sure if its just this example model that is at fault, or that my install is mixed up between pymc3 and pymc4. I was using pymc3 since the learning examples seem to be mostly pymc3, however I would be happy to migrate to pymc4 if the code transition is not too difficult.

Any ideas as to why the Bambi documentation example model 1 is failing? would give confidence to using other Bambi models. Thank you for expertise and guidance on the above. DD