hssm.graph() does not render in marimo notebook

[Jovan-Kemp]

Describe the bug
hssm.graph() does not render in a marimo notebook.

HSSM version
Version: 0.2.11

To Reproduce

import marimo as mo
import hssm
import numpy as np

v_true = 0.5
a_true = 1.5
z_true = 0.5
t_true = 0.5

param_dict_init = dict(
    v=v_true,
    a=a_true,
    z=z_true,
    t=t_true,
)


dataset_simulated_main = hssm.simulate_data(
    model="ddm",
    theta=param_dict_init,
    size=500,
)

simple_ddm_model = hssm.HSSM(data=dataset_simulated_main)
simple_ddm_model.graph()

Screenshots
Image within marimo environment with a convert to png solution.

Additional context
A similar problem was reported and fixed for pymc.Model: pymc-devs/pymc#7830

[digicosmos86]

Thanks @Jovan-Kemp for bringing this to our attention! I looked into this. and it seems to be an issue with bambi. Basically, when model.graph() is called, HSSM basically calls the .graph() method in bambi with a few custom changes and returns a Digraph object, which currently doesn't support marimo yet. The PyMC solution is to call model_to_mermaid and generates a mermaid graph, which marimo does support.

Here's what we might approach this:

1. We implement model_to_mermaid ourselves, which side-steps bambi and could create slight headache in terms of maintaining the code
2. We do nothing. Hopefully the Graphviz bindings for Python will support marimo in the long run. Looks like the marimo team is not working to fix this though... Unable to see graphviz output from PyMC marimo-team/marimo#4203

@AlexanderFengler let me know your thoughts