[optgrowth_fast/ogm_crra.py] Update np.random → Generator API

[Chihiro2000GitHub]

Summary

This PR migrates legacy NumPy random API usage in _static/lecture_specific/optgrowth_fast/ogm_crra.py as part of QuantEcon/meta#299. The legacy global random-state calls are replaced with an explicit np.random.default_rng() generator.

Details

• The random draw sits inside the @jitclass OptimalGrowthModel_CRRA.__init__. Following the QuantEcon jitclass convention, rng is passed in as an argument (not stored as a class attribute), and np.random.seed(seed) / np.random.randn(shock_size) are replaced with rng.standard_normal(shock_size).
• The seed parameter is dropped from the constructor; reproducibility now comes from the caller creating rng = np.random.default_rng(seed) and passing it in. This changes the __init__ signature (rng added, seed removed), so call sites must construct with OptimalGrowthModel_CRRA(rng).
• Within this repository, no lecture appears to :load:/reference optgrowth_fast/ogm_crra.py, so there are no in-repo call sites to update here. Any external call sites (e.g. in other lecture repos) will need to construct rng and pass it in.
• Verified locally that the sized rng.standard_normal(shock_size) call and passing a Generator into the @jitclass compile, run, and remain reproducible under Numba 0.62.1 (the same pattern was checked in the companion ogm.py PR).

Note for reviewers

While migrating I noticed a pre-existing bug unrelated to this change: u_prime_inv is defined as def u_prime_inv(c): (missing self) yet its body references self.γ, so calling it would raise NameError. I have left it untouched to keep this PR focused on the random API migration, but I'm happy to fix it here (or in a separate PR) if you'd prefer — just let me know.

Hi @mmcky and @HumphreyYang, I'd be grateful if you could take a look when you have time.

[github-actions]

📖 Netlify Preview Ready!

Preview URL: https://pr-963--sunny-cactus-210e3e.netlify.app

Commit: 84d292f

---

Build Info

• Workflow: Build Project [using jupyter-book]