rstan-to-pystan

Converting RStan to PyStan involves translating your Stan model (which remains unchanged), mapping hyperparameters like iter, warmup, chains, and seed to PyStan 3.x equivalents, and adapting data preparation and sampling calls to PyStan patterns. Validate sample outputs and formats match across the migration.

RStan hyperparameters like iter, warmup, chains, and seed map directly to PyStan 3.x, but their argument names and API structure differ between the two interfaces. The Skill maps these equivalents so your sampling configuration produces consistent results in Python.

Yes. Stan model blocks remain identical across RStan and PyStan; only the wrapper code and API calls change. Your .stan files don't require modification—you adapt how you instantiate, configure, and sample from the model in Python.

Migration includes consistency checks on sample extraction and output formats. Compare posterior distributions, effective sample sizes, and diagnostic metrics between RStan and PyStan runs to confirm the conversion preserved modeling behavior and numerical results.

Data dictionaries and input formats differ between RStan and PyStan 3.x. The migration process reconciles how you structure and pass data to the model, ensuring PyStan's data interface receives properly formatted inputs that match your Stan model's data block.

PyStan 3.x covers core RStan functionality, but API differences exist in configuration and method names. Pre-conversion validation identifies incompatibilities and confirms your RStan workflow has a supported PyStan equivalent before full translation.