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forrel vs ibdsim2

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

Shared themes:simulation

forrel vs ibdsim2: at a glance

Featureforrelibdsim2
SectorAnalyticsAnalytics
Velocity score0.02.5
Sparks · 30d00
Top themesforensic genetics, kinship analysis, simulation, parallel computingstatistical-genetics, pedigree-analysis, simulation, r-packages
Last editorial update39m ago1h ago
WebsiteVisit →Visit →

What is forrel?

forrel is getting faster at the simulations forensic kinship work actually spends its time on.

forrel handles forensic pedigree analysis: kinship likelihood ratios, profile simulation, relationship checking, and missing person calculations. Version 1.9.0 synced with pedtools 2.11.0's loop handling, which the release notes credit with enabling complex pedigrees that were previously intractable, and moved profileSim() to mirai for parallelism. It also added fEstimate() for inbreeding coefficients and parentChildLikelihood() as a fast path for the simplest case.

Read the full forrel 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 →

forrel vs ibdsim2: editorial side-by-side

F
forrel
ANALYTICS
0.0

forrel is getting faster at the simulations forensic kinship work actually spends its time on.

◆ Current state

forrel handles forensic pedigree analysis: kinship likelihood ratios, profile simulation, relationship checking, and missing person calculations. Version 1.9.0 synced with pedtools 2.11.0's loop handling, which the release notes credit with enabling complex pedigrees that were previously intractable, and moved profileSim() to mirai for parallelism. It also added fEstimate() for inbreeding coefficients and parentChildLikelihood() as a fast path for the simplest case.

◆ Where it's heading

Two long threads run through the window. One is making the common operations cheap: faster simulations through reorganized likelihood calculations, a dedicated parent-child path, dropped map attribute preservation, log-likelihoods to avoid underflow in kinshipLR(). The other is making relationship checking presentable, with checkPairwise() growing ggplot2 and plotly output, verbal relationship descriptions, and bootstrap p-values. Reference data is maintained alongside both, with the FORCE SNP panel completed and an X-chromosomal counterpart added.

◆ Prediction

With profileSim() on mirai and the loop handling synced, the next likely step is extending mirai parallelism to the other simulation-heavy functions such as exclusionPower() and the bootstrap in checkPairwise().

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 forrel 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 forrel or ibdsim2.

See all forrel alternatives → · See all ibdsim2 alternatives →

Recent activity from forrel 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. 1mo agoforrelmirai parallelism and faster profile simulation
  3. 8mo agoibdsim2Segment-distribution merge argument, and function-valued parameters
  4. 1y agoibdsim2Built-in decode19 recombination map rebuilt, cutting 38k points to 14k
  5. 1y agoforrelFORCE SNP panel completed and X-chromosomal set added
  6. 1y agoforrelrankProfiles() and access to special lumping
  7. 1y agoibdsim2Consistent IBD segment merging across the realised-coefficient functions
  8. 1y agoforrelacrossComps argument and readFam() unexported
  9. 1y agoibdsim2Built-in pedigree labels revised; extra inbred examples added
  10. 1y agoforrelcheckPairwise() overhauled with p-values and new plot backends
  11. 1y agoibdsim2The Shiny front end moves into the package and gains X-chromosomal simulation
  12. 2y agoforrelFamilias interoperability split into pedFamilias

Frequently asked questions

What is the difference between forrel and ibdsim2?

Both compete on the same themes — simulation — within Analytics. 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 forrel 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 forrel?

Top forrel alternatives in Analytics are ranked by recent ship velocity. Browse the "forrel alternatives" section above for the current picks, or visit /alternatives/forrel 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.