tern.rbmi
Reference-based multiple imputation tables, shipping only what CRAN checks demand.
Comparison · Analytics
CMAQ vs xts
A side-by-side editorial comparison of CMAQ and xts — release velocity, themes, recent moves, and the top alternatives to consider.
CMAQ vs xts: 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 xts?
xts is finished software, and its releases now track R's C API more than user requests.
xts is the time-series class underpinning much of R's financial stack, and it behaves like infrastructure: the visible releases are bug fixes, plotting repairs and conformance work. A recurring thread is removing calls R no longer considers public — SET_TYPEOF in 0.14.0 and 0.14.1, then ATTRIB() and SET_ATTRIB() in 0.14.2. Feature additions are rare and small, the last cluster being open-ended time-of-day subsetting and na.fill performance in 0.13.0.
CMAQ vs xts: 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.
xts
0.0ANALYTICS
xts is finished software, and its releases now track R's C API more than user requests.
◆ Current state
xts is the time-series class underpinning much of R's financial stack, and it behaves like infrastructure: the visible releases are bug fixes, plotting repairs and conformance work. A recurring thread is removing calls R no longer considers public — SET_TYPEOF in 0.14.0 and 0.14.1, then ATTRIB() and SET_ATTRIB() in 0.14.2. Feature additions are rare and small, the last cluster being open-ended time-of-day subsetting and na.fill performance in 0.13.0.
◆ Where it's heading
Two forces drive releases. R core keeps narrowing its public C API, and xts keeps rewriting internals to stay inside it; separately, ggplot-era changes elsewhere in the ecosystem surface plotting bugs that get fixed one report at a time. Nearly every entry credits an outside reporter, which is what maintenance of a dependency this widely used looks like.
◆ Prediction
Further C API conformance work is the safest expectation, since two consecutive releases have each removed a different non-API entry point and R has continued tightening that boundary.
Alternatives to CMAQ and xts
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 xts.
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.
Recent activity from CMAQ and xts
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 5mo agoxtsmulti.panel plots beyond 8 columns; SET_TYPEOF removed from C
- 5mo agoxtsATTRIB removed from C; rollapply.xts accepts vector widths
- 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 agoxtsMulti-panel event lines; first SET_TYPEOF replacement
- 2y agoxtstclass changes now alter index values; log-scale y-axis added
- 2y agoCMAQCMAQ 5.4.0.4 fixes RBSTATS under ROS3, corrects a molecular weight
- 3y agoxtsUpdate path for pre-0.12 objects missing index attributes
- 3y agoxtsOpen-ended time-of-day subsetting; fast scalar na.fill
Frequently asked questions
What is the difference between CMAQ and xts?
They serve adjacent needs but don't currently overlap on shipped themes. CMAQ and xts 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 xts?
Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. CMAQ and xts 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 xts?
Top xts alternatives in Analytics are ranked by recent ship velocity. Browse the "xts alternatives" section above for the current picks, or visit /alternatives/xts-r for the full list with editorial commentary on each.