inst/KERNELS_MAXIMA.md

In np: Nonparametric Kernel Smoothing Methods for Mixed Data Types

kernels.max Developer Notes

This file is a Maxima script used for symbolic derivation of higher-order kernel objects (kernel, derivative, CDF, and convolution expressions) and associated constants.

Purpose

• inst/kernels.max is developer tooling, not runtime package code.
• It is useful when extending or validating higher-order kernel algebra.
• It is not sourced by R code during normal package execution.

Typical Use

Install/launch Maxima from the official project page: https://maxima.sourceforge.io/

1. Open Maxima.
2. Load kernels.max.
3. Run computeKernels(<base_kernel>, <support>) for the desired kernel.
4. Capture symbolic/numeric output for:
5. order-2/4/6/8 kernel forms,
6. derivatives,
7. CDF forms,
8. convolution forms,
9. kernel constants.

Example Maxima session sketch:

load("kernels.max")$
computeKernels(epanechnikov, sqrt(5))$
computeKernels(gaussian, inf)$

Maintenance Guidance

• Treat outputs as algebraic reference material.
• Before integrating derived expressions into C/R code, verify:
• numerical parity against existing implementations,
• boundary/support behavior,
• objective-value parity in benchmark smoke tests.
• Keep any production code changes separate from symbolic scratch edits.

Scope Boundaries

• Keep this file for reproducibility of derivations.
• Do not rely on it as an executable part of package installation/runtime.

Canonical Implementation Directive (2026-03-05)

This repository follows a strict canonical execution rule:

1. One canonical implementation per method (outside explicit np.tree branching).
2. Unsupported configurations must fail fast with explicit stop(...) diagnostics.
3. No silent remap/coercion of user-selected options (for example bwmethod, regtype, kernels, cv.iterate, or bounds transforms).
4. No hidden alternate execution paths for the same method semantics.
5. All fit-defining options (for example degree, basis, bernstein.basis, kernels, and bounds) must be propagated and used by the canonical path.
6. np.tree=FALSE is the default; when np.tree=TRUE, behavior must remain semantics-preserving and option-compatible with the canonical path.
7. Remove or reject legacy/debug compatibility branches that add redundant runtime overhead once canonical behavior exists.

np documentation built on May 3, 2026, 1:07 a.m.