tern.rbmi
Reference-based multiple imputation tables, shipping only what CRAN checks demand.
Comparison · Analytics
CMAQ vs parallelDist
A side-by-side editorial comparison of CMAQ and parallelDist — release velocity, themes, recent moves, and the top alternatives to consider.
CMAQ vs parallelDist: at a glance
What is CMAQ?
CMAQ went global in v5.5, and has been patching that surface ever since.
CMAQ is the EPA's Community Multiscale Air Quality modeling system, used for regulatory and research air quality simulation. Its release rhythm is strictly two-tier: numbered major versions carry new science and fresh benchmark datasets, while the x.y.z.n updates carry bug fixes against documentation and benchmarks that stay pinned to the parent version. The current line is v5.5, which introduced CRACMM2 chemistry and coupling to MPAS-A meteorology, followed by three patch rollups.
What is parallelDist?
parallelDist is in pure preservation mode — one build fix every few years.
parallelDist computes distance matrices across threads in C++ via RcppParallel and Armadillo. The feature set has been settled since 0.2.3 in 2018, which added hamming distance and cosine similarity; everything after that is compatibility work. The most recent release, 0.2.7, exists only to drop a C++11 pin that newer Armadillo versions no longer tolerate.
CMAQ vs parallelDist: editorial side-by-side
CMAQ
0.0ANALYTICS
CMAQ went global in v5.5, and has been patching that surface ever since.
◆ Current state
CMAQ is the EPA's Community Multiscale Air Quality modeling system, used for regulatory and research air quality simulation. Its release rhythm is strictly two-tier: numbered major versions carry new science and fresh benchmark datasets, while the x.y.z.n updates carry bug fixes against documentation and benchmarks that stay pinned to the parent version. The current line is v5.5, which introduced CRACMM2 chemistry and coupling to MPAS-A meteorology, followed by three patch rollups.
◆ Where it's heading
The v5.5 patches cluster around the newest and most sensitive components. ISAM source apportionment and DDM-3D sensitivity analysis account for corrections in every one of the three updates, and CRACMM2 needed fixes within months of release. That is the expected shape after a major version lands: the science is stable, the instrumentation built on top of it is not. Parallel I/O work in the latest patch suggests the global configurations are now being run at scales that expose throughput limits.
◆ Prediction
The next major version will fold these fixes in with new science, documentation and benchmark data — the release notes state this explicitly each time. Until then, expect further ISAM and DDM-3D corrections, which have appeared in every patch so far.
parallelDist
0.0ANALYTICS
parallelDist is in pure preservation mode — one build fix every few years.
◆ Current state
parallelDist computes distance matrices across threads in C++ via RcppParallel and Armadillo. The feature set has been settled since 0.2.3 in 2018, which added hamming distance and cosine similarity; everything after that is compatibility work. The most recent release, 0.2.7, exists only to drop a C++11 pin that newer Armadillo versions no longer tolerate.
◆ Where it's heading
The package is being kept installable, not developed. The three most recent releases are a toolchain pin removal, a DESCRIPTION field removal, and a coercion change inherited from proxy — none originate from user-facing intent. Gaps of three to four years between releases are the norm now, and each one is triggered by something upstream breaking rather than by a roadmap.
◆ Prediction
The next release will almost certainly be another compatibility fix timed to whatever Armadillo, Rcpp or CRAN check policy changes next. Nothing in the entries points to new distance measures or API work.
Alternatives to CMAQ and parallelDist
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 CMAQ or parallelDist.
tern.mmrm
An MMRM tabulation package that has published nothing since its 2024 CRAN releases.
ggmagnify
A single-purpose ggplot2 inset tool, refining the same three arguments.
symengine
An R symbolic-maths binding whose changelog is really the C++ core's release notes.
gtfstools
gtfstools stopped guarding its own object model and started accepting everyone else's.
quantities
The glue package that makes R carry units and uncertainty through the same calculation.
See all CMAQ alternatives → · See all parallelDist alternatives →
Recent activity from CMAQ and parallelDist
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 10mo agoparallelDistparallelDist 0.2.7 drops the C++11 pin for newer Armadillo
- 1y agoCMAQCMAQ 5.5.0.3 enables parallel I/O, fixes DDM-3D control files
- 1y agoCMAQCMAQ 5.5.0.2 corrects ISAM aerosol and cloud processing
- 1y agoCMAQCMAQ 5.5.0.1 fixes SAPRC mechanism runs and NLCD mapping
- 1y agoCMAQCMAQ 5.5 adds global simulation coupled to MPAS-A ⚡
- 1y agoCMAQCMAQ 5.4.0.5: minor ELMO output fixes
- 2y agoCMAQCMAQ 5.4.0.4 fixes RBSTATS under ROS3, corrects a molecular weight
- 4y agoparallelDistparallelDist 0.2.6: LazyData removed, vignette font swapped
- 4y agoparallelDistparallelDist 0.2.5 changes cosine distance to 1-x
- 7y agoparallelDistparallelDist 0.2.4 fixes the Solaris build
- 7y agoparallelDistparallelDist 0.2.3 adds hamming and cosine measures
- 7y agoparallelDistparallelDist 0.2.2
Frequently asked questions
What is the difference between CMAQ and parallelDist?
They serve adjacent needs but don't currently overlap on shipped themes. CMAQ and parallelDist 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 CMAQ better than parallelDist?
Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. CMAQ and parallelDist 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 CMAQ?
Top CMAQ alternatives in Analytics are ranked by recent ship velocity. Browse the "CMAQ alternatives" section above for the current picks, or visit /alternatives/cmaq for the full list with editorial commentary on each.
What are the best alternatives to parallelDist?
Top parallelDist alternatives in Analytics are ranked by recent ship velocity. Browse the "parallelDist alternatives" section above for the current picks, or visit /alternatives/paralleldist for the full list with editorial commentary on each.