R Package Methods Check

Review the changed R package code with emphasis on methodological correctness, not style.

Use this for method changes, bug fixes that may affect inference, numerical refactors, API changes, or pre-PR review of an R package.

Focus on these questions:

1. Statistical correctness

• Are the assumptions in the code consistent with the stated method?
• Are parameterizations clear and internally consistent?
• Are transformations, offsets, scales, and links handled correctly?
• Are quantities on the correct scale when returned, printed, or plotted?
• Are defaults scientifically reasonable?
• Are estimated quantities distinguishable from inputs, hyperparameters, and diagnostics?
• Are uncertainty-related quantities labeled clearly and computed on the intended scale?
• Are implicit assumptions hidden in preprocessing, normalization, filtering, or pseudocounts?

2. Numerical stability and edge-case handling

• unstable subtraction, division, exponentiation, or log operations
• underflow/overflow risk
• division by zero or near-zero quantities
• unguarded log, exp, softmax, or likelihood calculations
• singular or near-singular matrix operations
• poor behavior for very small sample sizes
• problems induced by extreme counts, sparsity, or heavy skew
• failure to handle ties, all-zero rows, empty groups, or one-level factors
• silent recycling, coercion, or factor conversion issues
• missing handling for NA, NaN, Inf, -Inf

3. Package behavior

• Are exported vs internal functions appropriate?
• Are function names, arguments, and defaults coherent?
• Are argument checks informative and early?
• Are return values stable and documented?
• Is backward compatibility preserved where reasonable?
• Are S3/S4 methods registered correctly if relevant?
• Are dependencies necessary and minimal?
• Are examples safe, fast, and reproducible?

4. Tests

• Propose the smallest regression and edge-case tests that would catch real breakage.
• Prefer one minimal regression test over broad test-suite rewrites unless clearly needed.

5. Documentation

• Flag roxygen, examples, README, vignettes, and NEWS items that no longer match behavior.

Return exactly these sections:

Summary

2-4 sentences on what changed and the main risk.

Major issues

For each issue, give:

• Issue
• Why it matters
• Smallest fix

Suggested tests

List the minimal tests to add or update.

Documentation updates

List docs or examples that should be updated.

Nice-to-have improvements

Optional cleanup that is not required for correctness.

Behavior:

• Be skeptical about scientific correctness, not just syntax.
• Prefer the smallest correct patch.
• Distinguish correctness issues from maintainability issues.
• If uncertain, say exactly what is uncertain.
• Review first; do not start editing unless explicitly asked.