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Comparison · Infra & APIs
cofad vs RSA
A side-by-side editorial comparison of cofad and RSA — release velocity, themes, recent moves, and the top alternatives to consider.
Shared themes:maintenance
cofad vs RSA: at a glance
What is cofad?
Contrast analysis with a Shiny front end, shipping about one release a year
cofad performs contrast analyses for factorial designs in both between- and within-subject forms, and ships a Shiny GUI alongside the R interface. The 0.3.0 release in 2024 was the substantial one: a helper for calculating differences between two sets of lambdas for competing contrast analysis, improved summary output, removal of the plyr dependency, a rebuilt Shiny interface using standard elements after the sortable drag-and-drop proved unstable, and a change of maintainer to Johannes Titz. The most recent release is a one-line patch fixing degrees of freedom in the t-test table.
What is RSA?
Four years quiet, then two releases ninety seconds apart, both about drawing better plots
RSA implements response surface analysis for congruence questions in psychology, built on lavaan. After four and a half years of silence the maintainer pushed 0.10.6 and 0.10.8 within ninety seconds of each other on 2 October 2025, so the feed's version sequence is a backfill of accumulated work rather than two separate release events. Both are plotting releases: user-defined lines and points on the surface, stilts for selected data points, and separate control of point fill and border colour.
cofad vs RSA: editorial side-by-side
cofad
0.0INFRA · APIS
Contrast analysis with a Shiny front end, shipping about one release a year
◆ Current state
cofad performs contrast analyses for factorial designs in both between- and within-subject forms, and ships a Shiny GUI alongside the R interface. The 0.3.0 release in 2024 was the substantial one: a helper for calculating differences between two sets of lambdas for competing contrast analysis, improved summary output, removal of the plyr dependency, a rebuilt Shiny interface using standard elements after the sortable drag-and-drop proved unstable, and a change of maintainer to Johannes Titz. The most recent release is a one-line patch fixing degrees of freedom in the t-test table.
◆ Where it's heading
Development is slow and correctness-led. The record runs from a JOSS publication in 2021 through a near three-year gap to a release that both extended the method and repaired the GUI, then a degrees-of-freedom fix. Maintainer and author order changed in 0.3.0, which typically marks a handover rather than a burst of new work, and the cadence since is consistent with that.
◆ Prediction
Expect low-frequency correctness releases; the competing contrast analysis helper added in 0.3.0 is the most likely thing to be extended if anything is.
RSA
0.0INFRA · APIS
Four years quiet, then two releases ninety seconds apart, both about drawing better plots
◆ Current state
RSA implements response surface analysis for congruence questions in psychology, built on lavaan. After four and a half years of silence the maintainer pushed 0.10.6 and 0.10.8 within ninety seconds of each other on 2 October 2025, so the feed's version sequence is a backfill of accumulated work rather than two separate release events. Both are plotting releases: user-defined lines and points on the surface, stilts for selected data points, and separate control of point fill and border colour.
◆ Where it's heading
The statistical core has been stable since 0.10.0 in 2020, which added control variables, pooled centering and a corrected AICc. Everything since is either plot customisation or a reaction to a dependency — lavaan model comparison, rgl deprecations, tkrplot on Apple Silicon, the ggplot2 fill aesthetic. This is a mature method implementation in maintenance, where the visible work is making its surface plots publishable.
◆ Prediction
Further releases are most likely dependency reactions, with rgl and ggplot2 the two that have repeatedly forced changes, and plot customisation arriving in batches whenever the maintainer returns to the package.
Alternatives to cofad and RSA
Other Infra & APIs 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 cofad or RSA.
Cursor
Cursor's agents stop waiting to be asked - they subscribe, and they hold a goal until it's done.
incident.io
Nexus does the diagnosis; the agent is now reaching into the status page too.
Warp
Warp turned its quarter of software-factory essays into infrastructure you can buy.
Okta
Okta's developer blog is a Cross App Access campaign, now diluted by advocacy-team storytelling.
tealeaves
A leaf-temperature model that finished its job in 2020 and has stayed finished
Recent activity from cofad and RSA
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 10mo agoRSAUser-defined lines and points on response surface plots
- 10mo agoRSAStilts and separate point fill and border colours in plotRSA
- 1y agocofadDegrees of freedom corrected in the t-test table
- 2y agocofadCompeting contrast helper, rebuilt Shiny GUI, maintainer change
- 4y agocofadDocumentation and references for JOSS publication
- 4y agocofadShiny GUI added; aggregated-data function and 0-variance fix
- 5y agoRSADemo dataset for control variables and cubic RSA; SRSQD fix
- 5y agoRSAtkrplot moved to Suggests for Apple Silicon
- 6y agoRSAFixes for R 4.0.0 stringsAsFactors and discrepancy output
- 6y agoRSAControl variables, pooled centering and a corrected AICc
Frequently asked questions
What is the difference between cofad and RSA?
Both compete on the same themes — maintenance — within Infra & APIs. cofad and RSA are shipping at a similar cadence (velocity 0.0 vs 0.0, both within Sparkpulse's "active" band). See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.
Is cofad better than RSA?
Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. cofad and RSA are shipping at a similar cadence (velocity 0.0 vs 0.0, both within Sparkpulse's "active" band). For your specific use case, the alternatives sections above list other Infra & APIs products to evaluate alongside.
What are the best alternatives to cofad?
Top cofad alternatives in Infra & APIs are ranked by recent ship velocity. Browse the "cofad alternatives" section above for the current picks, or visit /alternatives/cofad for the full list with editorial commentary on each.
What are the best alternatives to RSA?
Top RSA alternatives in Infra & APIs are ranked by recent ship velocity. Browse the "RSA alternatives" section above for the current picks, or visit /alternatives/rsa for the full list with editorial commentary on each.