cIRT
A choice-based IRT model published once in 2019 and kept compiling ever since
Comparison · Analytics
fmtr vs SSN2
A side-by-side editorial comparison of fmtr and SSN2 — release velocity, themes, recent moves, and the top alternatives to consider.
Shared themes:r-package
fmtr vs SSN2: at a glance
What is fmtr?
Rebuilding SAS's formatting layer in R, one format specification at a time
fmtr applies formats to R data the way SAS applies them: named format catalogues, format lists, and an fapply() that maps a specification onto a vector. It is part of a family of packages that reconstruct SAS reporting idioms in R, and it shares infrastructure with them — labels.data.frame() was moved out to the common package, which fmtr now depends on. The recent releases have been closing specific gaps against SAS's own format vocabulary.
What is SSN2?
Stream-network spatial models learning to run on data that no longer fits in memory
SSN2 fits spatial statistical models on stream networks, where covariance follows flow-connected distance along the network rather than straight-line distance. It is the maintained successor to the original SSN package, published through JOSS in 2024, and leans on spmodel for its underlying model machinery. Recent releases have concentrated on the constraint that binds this class of model hardest: the distance matrix.
fmtr vs SSN2: editorial side-by-side
fmtr
0.0ANALYTICS
Rebuilding SAS's formatting layer in R, one format specification at a time
◆ Current state
fmtr applies formats to R data the way SAS applies them: named format catalogues, format lists, and an fapply() that maps a specification onto a vector. It is part of a family of packages that reconstruct SAS reporting idioms in R, and it shares infrastructure with them — labels.data.frame() was moved out to the common package, which fmtr now depends on. The recent releases have been closing specific gaps against SAS's own format vocabulary.
◆ Where it's heading
The direction is parity, pursued in small increments. Quarter format codes were added because base R has none; the SAS best. format was reimplemented, then hardened against the variations people actually write; statistical summary helpers like fmt_mean_sd() and fmt_mean_stderr() cover the cell contents clinical tables need. The structural work is largely behind it, including the breaking 2022 move that handed labelling to a sibling package, so what remains is vocabulary coverage.
◆ Prediction
The pattern of adding a SAS format, then a release to handle its variants, suggests the next releases continue filling in format codes and summary helpers rather than changing how formats are applied.
SSN2
0.0ANALYTICS
Stream-network spatial models learning to run on data that no longer fits in memory
◆ Current state
SSN2 fits spatial statistical models on stream networks, where covariance follows flow-connected distance along the network rather than straight-line distance. It is the maintained successor to the original SSN package, published through JOSS in 2024, and leans on spmodel for its underlying model machinery. Recent releases have concentrated on the constraint that binds this class of model hardest: the distance matrix.
◆ Where it's heading
The first year was about establishing credibility and interoperability — a JOSS review, geopackage import support, deprecation of the SSN-to-SSN2 bridge, marginal means through emmeans. The 2025 releases turn to scale, moving distance matrices onto disk via filematrix and routing estimation and prediction through the local approximation. The 0.4.0 default change is the visible consequence: the neighbourhood size rises from 100 to 200, buying accuracy now that the surrounding machinery can afford it.
◆ Prediction
With the large-data path established and its default just retuned, the next work most likely tightens that approximation further or extends it to the model classes the local argument does not yet cover.
Alternatives to fmtr and SSN2
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 fmtr or SSN2.
MetaboAnalystR
The R engine behind MetaboAnalyst closes the gap from raw spectra to biological interpretation
betaselectr
Standardised coefficients for models where standardising everything is wrong — but the feed only links out
BiocManager
Bioconductor's installer, frozen at 1.30.x and tuned almost entirely through environment variables
dcurves
Decision curve analysis, settled since 2022 and now moving only when its neighbours do
hubAdmin
The config-authoring half of hubverse, pinned to whatever the schema is doing this quarter
Recent activity from fmtr and SSN2
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 9mo agoSSN2Local neighbourhood default doubled to 200
- 10mo agofmtrMean and standard error helper, plus best-format variants
- 10mo agoSSN2partition_factor regression fixed, spmodel floor raised
- 11mo agofmtrSAS best. format reimplemented in fapply()
- 0y agoSSN2On-disk distance matrices lift the large-data ceiling
- 1y agoSSN2Numeric stability fix for beta-family models
- 2y agoSSN2Geopackage import support and the JOSS review release
- 2y agoSSN2Snapshot tag marking JOSS acceptance
- 2y agofmtrQuarter format codes %q and %Q added
- 2y agofmtrFormat lists become readable and writable files
- 2y agofmtrDocumentation and examples expanded
- 2y agofmtrvalue() can return results as a factor
Frequently asked questions
What is the difference between fmtr and SSN2?
Both compete on the same themes — r-package — within Analytics. fmtr and SSN2 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 fmtr better than SSN2?
Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. fmtr and SSN2 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 Analytics products to evaluate alongside.
What are the best alternatives to fmtr?
Top fmtr alternatives in Analytics are ranked by recent ship velocity. Browse the "fmtr alternatives" section above for the current picks, or visit /alternatives/fmtr for the full list with editorial commentary on each.
What are the best alternatives to SSN2?
Top SSN2 alternatives in Analytics are ranked by recent ship velocity. Browse the "SSN2 alternatives" section above for the current picks, or visit /alternatives/ssn2 for the full list with editorial commentary on each.