NEWS.md

In psp: Parameter Space Partitioning MCMC for Global Model Evaluation

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

psp (development version)

psp 1.0.6 (2026-10-06)

Sampling results differ from 1.0.5 for the same seed, because the fixes below change the path the sampler takes.

Added

• A package website at https://lenarddome.com/psp/, built with pkgdown and deployed to GitHub Pages, with a tutorial that partitions the parameter space of prospect theory and a benchmark report comparing 1.0.6 to 1.0.5.
• The benchmark results and the scripts that produce them in benchmarks/.
• A recipe that partitions ALCOVE's parameter space on the six Shepard, Hovland and Jenkins (1961) problems, following Pitt et al. (2006), with the scripts and saved results it reads in vignettes/articles/alcove/.
• benchmarks/benchmark.R for comparing the speed of two builds of the package.
• Tests for the sampler's invariants (centres, counts, saved output, pattern identity, control validation) and for the contract with model and discretize.

Changed

• The pspGlobal() documentation cites the published version of g-distance (Dome & Wills, 2025, Psychological Review) instead of the preprint.
• pspGlobal matches ordinal patterns with a hash table in a single pass instead of five pairwise comparison loops over every stored pattern, and no longer copies the stored patterns on every iteration.
• model and discretize are called through one error-protected block per iteration instead of one per call, which removes two setjmp system calls per evaluation on macOS.
• Output files are opened once per run instead of on every write, and each row is written in a single call.
• Saved csv values are formatted with std::to_chars where the compiler supports it (macOS 13.3 or later, libstdc++ 11 or later), which makes writing them about 5 times faster than in 1.0.5. Other platforms use %.17g, which is about 45% slower than 1.0.5 because it writes full precision.
• model output of the wrong length or type, and discretize output that is not a dimensionality x dimensionality numeric matrix, now stop with a message that names the problem instead of an Armadillo error.

Fixed

• New ordinal patterns were sampled from the wrong centre: LastEvaluatedParameters appended rows for stored patterns that were not seen instead of for new patterns, so up to half of the newly discovered regions were explored from a point in another region. Each pattern's centre is now the last parameter set that produced it.
• The first ordinal pattern was counted one extra time.
• The first iteration only proposed from the first pattern instead of from every underpopulated pattern found by init.
• Identical ordinal patterns containing NaN were stored as a new pattern on every evaluation.
• Saved csv files rounded parameters and model outputs to 6 significant digits; they are now written with full double precision, which makes the files about 2.7 times larger.

psp 1.0.5 (2026-01-15)

Changed

• Modernize tests by removing deprecated testthat::context() usage (84d0b19).
• Keep src/Makevars minimal, linking LAPACK, BLAS and FLIBS only (97cf4e9).

Fixed

• Armadillo helper edge cases in pspGlobal that caused null subviews and undefined behaviour (e60c3b3, 4ac2b01).

psp 1.0.2 (2024-07-24)

This is the last feature update from me. If you want to add new features, please get in touch (@lenarddome).

Fixed

• Continuous model output was not updated after the first iteration (69ed028).
• Typo in the package documentation (67fa59d).

psp 1.0.0 (2023-08-17)

Released on CRAN. This version introduces API-breaking changes. For a full list of feature changes since the previous CRAN release, see docs/CHANGELOG.md.

Added

• Model outputs (continuous variables) can be saved to disk (6d51dce).
• Multiple starting points can be defined for the sampling (d407392).

Changed

• Breaking: model evaluation functions are separated from discretization functions (6d51dce).

psp 0.5.8 (2022-08-16)

Added

• A C++ implementation of the parameter space partitioning routine, pspGlobal, that will take over from psp_global and psp_control (c75d02f).
• pspGlobal returns the number of iterations run (3b3bd0d).

Changed

• NA values are not allowed in model outputs (8ee7247).

Deprecated

• psp_global now shows a deprecation message. It will be removed once pspGlobal is complete (b52126d).

Removed

• The S3 class, to avoid redundancy and feature creep (c0f5f92).

Fixed

• The global R seed interfered with random sampling (358eee7).
• pspGlobal recruited unique inequality matrices more than once (5693543).
• Population parameters had no effect (5693543, 7648f47).

psp documentation built on Oct. 13, 2026, 5:07 p.m.