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CMAQ vs grex

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

CMAQ vs grex: at a glance

FeatureCMAQgrex
SectorAnalyticsAnalytics
Velocity score0.00.0
Sparks · 30d00
Top themesair-quality, atmospheric-modeling, epa, scientific-computinggtex, gene-annotation, bioinformatics, reference-data
Last editorial update1h ago1h ago
WebsiteVisit →Visit →

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.

Read the full CMAQ trajectory →

What is grex?

grex is a lookup table with a version number — it ships when the annotation moves.

grex converts the deprecated Ensembl gene IDs found in GTEx data into current gene symbols and identifiers, using org.Hs.eg.db as its reference. Its value is entirely in that bundled reference data, so a release either refreshes the mapping or does nothing to it. The 2025 release does nothing to it: GitHub Actions for the docs site, a check-note fix, and a smaller vignette.

Read the full grex trajectory →

CMAQ vs grex: editorial side-by-side

C
CMAQ
ANALYTICS
0.0

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.

G
grex
ANALYTICS
0.0

grex is a lookup table with a version number — it ships when the annotation moves.

◆ Current state

grex converts the deprecated Ensembl gene IDs found in GTEx data into current gene symbols and identifiers, using org.Hs.eg.db as its reference. Its value is entirely in that bundled reference data, so a release either refreshes the mapping or does nothing to it. The 2025 release does nothing to it: GitHub Actions for the docs site, a check-note fix, and a smaller vignette.

◆ Where it's heading

The annotation refreshes stopped. Between 2017 and 2019 the package tracked org.Hs.eg.db through four versions and added the GTEx V7 identifier set; since then the reference has stood still while the releases turned to packaging. That gap matters more here than it would elsewhere — a stale mapping table silently returns outdated symbols rather than failing, so the package's core asset ages invisibly.

◆ Prediction

Nothing in these entries signals a planned data refresh, and the six-year pattern suggests the next release will again be infrastructure. Users needing current annotations should check which org.Hs.eg.db version is bundled rather than assume the version number reflects it.

Alternatives to CMAQ and grex

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 grex.

See all CMAQ alternatives → · See all grex alternatives →

Recent activity from CMAQ and grex

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

  1. 1y agogrexgrex 1.9.1: pkgdown on Actions, smaller vignette
  2. 1y agoCMAQCMAQ 5.5.0.3 enables parallel I/O, fixes DDM-3D control files
  3. 1y agoCMAQCMAQ 5.5.0.2 corrects ISAM aerosol and cloud processing
  4. 1y agoCMAQCMAQ 5.5.0.1 fixes SAPRC mechanism runs and NLCD mapping
  5. 1y agoCMAQCMAQ 5.5 adds global simulation coupled to MPAS-A
  6. 1y agoCMAQCMAQ 5.4.0.5: minor ELMO output fixes
  7. 2y agoCMAQCMAQ 5.4.0.4 fixes RBSTATS under ROS3, corrects a molecular weight
  8. 7y agogrexgrex 1.9 refreshes the reference to org.Hs.eg.db 3.8.2
  9. 8y agogrexgrex 1.8 adds GTEx V7 IDs, updates to org.Hs.eg.db 3.6.0
  10. 8y agogrexgrex 1.7 updates the reference to org.Hs.eg.db 3.4.2
  11. 8y agogrexgrex 1.6 drops Google Fonts from vignettes
  12. 9y agogrexgrex 1.5 adds a pkgdown site and refreshes the reference

Frequently asked questions

What is the difference between CMAQ and grex?

They serve adjacent needs but don't currently overlap on shipped themes. CMAQ and grex 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 grex?

Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. CMAQ and grex 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 grex?

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