Add per-harmonic ridge_weights support and document PowerShell ridge env vars

[pukpr]

Motivation

• Provide fine-grained per-column ridge regularization so higher harmonics can be penalized differently than fundamentals.
• Ensure the intercept remains unpenalized when callers supply a full per-column ridge vector.
• Make it easy to run the example locally on PowerShell by documenting the new ridge-related environment variables.

Description

• Extended fit_sinusoidal_regression(...) to accept ridge_weights, validate that its length matches the design matrix columns, build a diagonal regularization matrix from it, and copy-and-zero the first entry when intercept=True so the intercept is not penalized; scalar ridge behavior is preserved as a fallback.
• In examples/mlr/lte_mlr.py added parameter reads for Ridge_Base, Ridge_Growth, Ridge_Free, Ridge_Exponent, and Ridge_Linear, computed ridge_weights in the design-matrix order (intercept, sin/cos pairs per harmonic, then linear X), applied a zero penalty for the first Ridge_Free harmonics (and harmonic 1 by default), and passed ridge_weights into fit_sinusoidal_regression(...).
• Updated examples/mlr/index.md to include a PowerShell snippet that sets example values for Ridge_Base, Ridge_Growth, Ridge_Free, Ridge_Exponent, and Ridge_Linear so users can reproduce the behavior locally.
• Minor trailing-newline/print tweak in examples/mlr/sinusoidal_regression.py.

Testing

• No automated tests were run.

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Codex Task

[Copilot]

Pull request overview

This PR extends the sinusoidal regression functionality to support per-harmonic ridge regularization weights and documents PowerShell environment variables for ridge parameters.

Changes:

• Added ridge_weights parameter to fit_sinusoidal_regression for per-column regularization control with automatic intercept exclusion
• Extended lte_mlr.py to compute ridge weights based on harmonic number with configurable base, growth, exponent, and free-harmonic parameters
• Added PowerShell environment variable examples for Ridge parameters in the documentation

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 6 comments.

File	Description
examples/mlr/sinusoidal_regression.py	Added ridge_weights parameter with validation and automatic intercept handling in ridge regularization
examples/mlr/lte_mlr.py	Added Ridge parameter reading and ridge_weights calculation logic with per-harmonic penalty computation
examples/mlr/index.md	Added PowerShell environment variable examples for Ridge_Base, Ridge_Growth, Ridge_Free, Ridge_Exponent, and Ridge_Linear

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[Copilot]

@pukpr I've opened a new pull request, #46, to work on those changes. Once the pull request is ready, I'll request review from you.

[Copilot]

@pukpr I've opened a new pull request, #47, to work on those changes. Once the pull request is ready, I'll request review from you.

[Copilot]

@pukpr I've opened a new pull request, #48, to work on those changes. Once the pull request is ready, I'll request review from you.

[Copilot]

@pukpr I've opened a new pull request, #49, to work on those changes. Once the pull request is ready, I'll request review from you.