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constants vs ibdsim2

A side-by-side editorial comparison of constants and ibdsim2 — release velocity, themes, recent moves, and the top alternatives to consider.

constants vs ibdsim2: at a glance

Featureconstantsibdsim2
SectorAnalyticsAnalytics
Velocity score0.02.5
Sparks · 30d00
Top themesphysical-constants, codata, units, uncertainty-propagationstatistical-genetics, pedigree-analysis, simulation, r-packages
Last editorial update14h ago49m ago
WebsiteVisit →Visit →

What is constants?

The R package for CODATA constants rebuilt its symbol table on NIST's naming so future updates stop being hand work.

constants exposes the CODATA recommended values of the physical constants to R, as a data frame plus symbol lists that carry units, uncertainties, or both. The package reached 1.0.0 on the 2018 CODATA release and has shipped once since, purely to track a units package update. Its surface is small and its release cadence is bound to CODATA, which revises every few years.

Read the full constants trajectory →

What is ibdsim2?

A pedigree IBD simulator that absorbed its own web app and now optimises for dense marker panels.

ibdsim2 simulates identity-by-descent sharing along chromosomes for arbitrary pedigrees, in both autosomal and X-chromosomal form, with downstream tools for segment statistics, pattern finding and distribution plots. Since 2.1.0 the Shiny front end lives inside the package and launches via launchApp() rather than sitting in a separate repository. The latest release is performance work, with profileSimIBD() substantially sped up for dense marker panels and ibdsim() skipping recombination in pedigree branches that cannot affect the result.

Read the full ibdsim2 trajectory →

constants vs ibdsim2: editorial side-by-side

C
constants
ANALYTICS
0.0

The R package for CODATA constants rebuilt its symbol table on NIST's naming so future updates stop being hand work.

◆ Current state

constants exposes the CODATA recommended values of the physical constants to R, as a data frame plus symbol lists that carry units, uncertainties, or both. The package reached 1.0.0 on the 2018 CODATA release and has shipped once since, purely to track a units package update. Its surface is small and its release cadence is bound to CODATA, which revises every few years.

◆ Where it's heading

The direction set at 1.0.0 was to stop being a curated convenience wrapper and become a mechanical mirror of NIST. Hand-crafted symbol names were replaced with NIST's own ASCII symbols, categories adopted NIST's, and uncertainty switched from relative to absolute — all framed by the maintainer as necessary to make future CODATA updates routine. On top of that the package gained a correlation matrix and optional integration with the quantities package, moving it from a lookup table toward something that can propagate uncertainty.

◆ Prediction

Having rebuilt the symbol table specifically so CODATA revisions become mechanical, the next substantive release most likely tracks a new CODATA dataset rather than adding API. The experimental correlated-value support, disabled by default at 1.0.0, is the one part these entries flag as unfinished.

I
ibdsim2
ANALYTICS
2.5

A pedigree IBD simulator that absorbed its own web app and now optimises for dense marker panels.

◆ Current state

ibdsim2 simulates identity-by-descent sharing along chromosomes for arbitrary pedigrees, in both autosomal and X-chromosomal form, with downstream tools for segment statistics, pattern finding and distribution plots. Since 2.1.0 the Shiny front end lives inside the package and launches via launchApp() rather than sitting in a separate repository. The latest release is performance work, with profileSimIBD() substantially sped up for dense marker panels and ibdsim() skipping recombination in pedigree branches that cannot affect the result.

◆ Where it's heading

Two long-running threads. One is the app as a first-class part of the package, which has been getting input validation, dependency checks and plotting fixes release after release, treating a research GUI as software to be maintained rather than a demo. The other is numerical care: the built-in recombination map was rebuilt in 2.3.0 with better chromosome endpoints and a thinning algorithm that cut it from about 38,000 points to 14,000 without losing accuracy, and IBD segment merging has been made consistent across the realised-coefficient functions. The maintainer flags repeatedly that seeded results may differ across versions, which is the right disclosure for a simulator used in published analyses.

◆ Prediction

The recent work points at further speed on dense panels and continued hardening of app input handling, both of which have appeared in each of the last several releases. Nothing here signals a new modelling capability on the way.

Alternatives to constants and ibdsim2

Other Analytics products tracked by Sparkpulse, ranked by recent ship velocity. Each card links to a full editorial trajectory and lets you pivot into a head-to-head comparison with either constants or ibdsim2.

See all constants alternatives → · See all ibdsim2 alternatives →

Recent activity from constants and ibdsim2

Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.

  1. 11d agoibdsim2profileSimIBD() sped up for dense marker panels; segment merging fixed
  2. 8mo agoibdsim2Segment-distribution merge argument, and function-valued parameters
  3. 1y agoibdsim2Built-in decode19 recombination map rebuilt, cutting 38k points to 14k
  4. 1y agoibdsim2Consistent IBD segment merging across the realised-coefficient functions
  5. 1y agoibdsim2Built-in pedigree labels revised; extra inbred examples added
  6. 1y agoibdsim2The Shiny front end moves into the package and gains X-chromosomal simulation
  7. 5y agoconstantsCompatibility fix for units 0.7-0
  8. 5y agoconstantsconstants 1.0.0
  9. 8y agoconstantsUnit handling fixes ahead of the 1.0.0 rebuild

Frequently asked questions

What is the difference between constants and ibdsim2?

They serve adjacent needs but don't currently overlap on shipped themes. ibdsim2 is currently shipping more aggressively (velocity 2.5 vs 0.0), with 0 editorial sparks in the last 30 days against 0. See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.

Is constants better than ibdsim2?

Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. ibdsim2 is currently shipping more aggressively (velocity 2.5 vs 0.0), with 0 editorial sparks in the last 30 days against 0. For your specific use case, the alternatives sections above list other Analytics products to evaluate alongside.

What are the best alternatives to constants?

Top constants alternatives in Analytics are ranked by recent ship velocity. Browse the "constants alternatives" section above for the current picks, or visit /alternatives/constants-r for the full list with editorial commentary on each.

What are the best alternatives to ibdsim2?

Top ibdsim2 alternatives in Analytics are ranked by recent ship velocity. Browse the "ibdsim2 alternatives" section above for the current picks, or visit /alternatives/ibdsim2 for the full list with editorial commentary on each.