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CMAQ vs quantities

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

CMAQ vs quantities: at a glance

FeatureCMAQquantities
SectorAnalyticsAnalytics
Velocity score0.00.0
Sparks · 30d00
Top themesair-quality, atmospheric-modeling, epa, scientific-computingunits, measurement-uncertainty, error-propagation, r-package
Last editorial update1h ago44m 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 quantities?

The glue package that makes R carry units and uncertainty through the same calculation.

quantities combines the units and errors packages into one class so values keep both their measurement units and their uncertainty through arithmetic, subsetting and data frame operations. Recent releases have been narrow: fixes to the covariance and correlation implementations, and performance work on the data.frame methods. Most of the release traffic is coordination with its two parent packages.

Read the full quantities trajectory →

CMAQ vs quantities: 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.

Q
quantities
ANALYTICS
0.0

The glue package that makes R carry units and uncertainty through the same calculation.

◆ Current state

quantities combines the units and errors packages into one class so values keep both their measurement units and their uncertainty through arithmetic, subsetting and data frame operations. Recent releases have been narrow: fixes to the covariance and correlation implementations, and performance work on the data.frame methods. Most of the release traffic is coordination with its two parent packages.

◆ Where it's heading

The design settled with 0.2.0, which made uncertainty unit-aware and added correlation and covariance support for quantities objects. Since then the package behaves like the integration layer it is — releasing when units, errors, dplyr or ggplot2 shift underneath it rather than on its own schedule. Several releases consist only of test repairs against upstream changes.

◆ Prediction

Expect the next release to follow a units or errors change rather than introduce new behaviour of its own.

Alternatives to CMAQ and quantities

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 quantities.

See all CMAQ alternatives → · See all quantities alternatives →

Recent activity from CMAQ and quantities

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

  1. 1y agoCMAQCMAQ 5.5.0.3 enables parallel I/O, fixes DDM-3D control files
  2. 1y agoCMAQCMAQ 5.5.0.2 corrects ISAM aerosol and cloud processing
  3. 1y agoCMAQCMAQ 5.5.0.1 fixes SAPRC mechanism runs and NLCD mapping
  4. 1y agoquantitiesFixes covariance and correlation implementations
  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 agoquantitiesFaster data.frame methods
  8. 2y agoCMAQCMAQ 5.4.0.4 fixes RBSTATS under ROS3, corrects a molecular weight
  9. 3y agoquantitiesTest fixes for an upstream units change
  10. 3y agoquantitiesUncertainty becomes unit-aware; adds correlation support
  11. 5y agoquantitiesCompatibility fix for units 0.7-0
  12. 6y agoquantitiesFixes uncertainty propagation for offset unit conversions

Frequently asked questions

What is the difference between CMAQ and quantities?

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

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

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