Historical Record: Removal of :load: Directives in Cake Eating Series (PR #679)

Context

As part of PR #679 (Refactor optimal growth lectures into unified cake eating series), we removed all :load: directives from the affected lectures and inlined the code directly.

Motivation

The :load: directive was removed to make lectures:

1. Self-contained - All code visible in the lecture file itself
2. Compatible with jupytext - Enables easy conversion to executable Python with jupytext --to py
3. Easier to maintain - No need to track external code files

Lectures That Had :load: Directives Removed

Lecture File	External Code File(s) Loaded	Purpose
cake_eating_numerical.md	_static/lecture_specific/cake_eating_numerical/analytical.py	Analytical solutions (c_star, v_star functions)
cake_eating_stochastic.md (formerly optgrowth.md)	_static/lecture_specific/optgrowth/cd_analytical.py	Analytical solutions for Cobb-Douglas case
cake_eating_stochastic.md	_static/lecture_specific/optgrowth/solve_model.py	solve_model() function for value function iteration
cake_eating_time_iter.md (formerly coleman_policy_iter.md)	_static/lecture_specific/optgrowth/cd_analytical.py	Analytical solutions
cake_eating_egm.md (formerly egm_policy_iter.md)	_static/lecture_specific/optgrowth/cd_analytical.py	Analytical solutions
cake_eating_egm.md	_static/lecture_specific/coleman_policy_iter/solve_time_iter.py	solve_model_time_iter() function
ifp.md	_static/lecture_specific/coleman_policy_iter/solve_time_iter.py	solve_model_time_iter() function
ifp.md	_static/lecture_specific/cake_eating_numerical/analytical.py	Analytical solutions for cake eating
optgrowth_fast.md (deleted)	_static/lecture_specific/optgrowth_fast/ogm.py	OptimalGrowthModel class
optgrowth_fast.md (deleted)	_static/lecture_specific/optgrowth_fast/ogm_crra.py	OptimalGrowthModel_CRRA class
optgrowth_fast.md (deleted)	_static/lecture_specific/optgrowth/cd_analytical.py	Analytical solutions
optgrowth_fast.md (deleted)	_static/lecture_specific/optgrowth/solve_model.py	solve_model() function

External Code Files That Were Loaded

• _static/lecture_specific/cake_eating_numerical/analytical.py
• _static/lecture_specific/optgrowth/cd_analytical.py
• _static/lecture_specific/optgrowth/solve_model.py
• _static/lecture_specific/coleman_policy_iter/solve_time_iter.py
• _static/lecture_specific/optgrowth_fast/ogm.py
• _static/lecture_specific/optgrowth_fast/ogm_crra.py

Files Deleted

The following external Python files were deleted after their content was inlined:

• _static/lecture_specific/cake_eating_numerical/analytical.py
• _static/lecture_specific/optgrowth/cd_analytical.py
• _static/lecture_specific/optgrowth/solve_model.py

Impact

• 8 lecture files had :load: directives removed
• All affected lectures now contain inline code
• No functionality changed - only code organization
• Lectures are now fully executable via jupytext --to py lectures/filename.md

Related

• PR #679: Refactor optimal growth lectures into unified cake eating series
• Comment from @jstac: "I really need to be able to easily generate executable code via jupytext --to py..."

Future Considerations

Going forward, we should prefer inline code over external :load: files for:

• Better jupytext compatibility
• Improved readability (all code visible in context)
• Easier maintenance

The :load: directive may still be useful for:

• Very large helper modules (>100 lines)
• Code shared across many lectures (though this should be in a proper Python package)
• Utility functions that would clutter the pedagogical flow

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This issue serves as historical documentation and does not require action.

No contribution is requested: this issue records the completed changes from PR #679. Read the listed cake-eating lecture files and related external Python paths only if you need historical context; the documented outcome is that the directives were removed and the issue requires no further work.