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constants vs quantities

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

Shared themes:units

constants vs quantities: at a glance

Featureconstantsquantities
SectorAnalyticsAnalytics
Velocity score0.00.0
Sparks · 30d00
Top themesphysical-constants, codata, units, uncertainty-propagationunits, measurement-uncertainty, error-propagation, r-package
Last editorial update47m ago1h ago
WebsiteVisit →Visit →

What is constants?

The R package for CODATA constants rebuilt its symbol table on NIST's naming so future updates stop being hand work.

constants exposes the CODATA recommended values of the physical constants to R, as a data frame plus symbol lists that carry units, uncertainties, or both. The package reached 1.0.0 on the 2018 CODATA release and has shipped once since, purely to track a units package update. Its surface is small and its release cadence is bound to CODATA, which revises every few years.

Read the full constants 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 →

constants vs quantities: editorial side-by-side

C
constants
ANALYTICS
0.0

The R package for CODATA constants rebuilt its symbol table on NIST's naming so future updates stop being hand work.

◆ Current state

constants exposes the CODATA recommended values of the physical constants to R, as a data frame plus symbol lists that carry units, uncertainties, or both. The package reached 1.0.0 on the 2018 CODATA release and has shipped once since, purely to track a units package update. Its surface is small and its release cadence is bound to CODATA, which revises every few years.

◆ Where it's heading

The direction set at 1.0.0 was to stop being a curated convenience wrapper and become a mechanical mirror of NIST. Hand-crafted symbol names were replaced with NIST's own ASCII symbols, categories adopted NIST's, and uncertainty switched from relative to absolute — all framed by the maintainer as necessary to make future CODATA updates routine. On top of that the package gained a correlation matrix and optional integration with the quantities package, moving it from a lookup table toward something that can propagate uncertainty.

◆ Prediction

Having rebuilt the symbol table specifically so CODATA revisions become mechanical, the next substantive release most likely tracks a new CODATA dataset rather than adding API. The experimental correlated-value support, disabled by default at 1.0.0, is the one part these entries flag as unfinished.

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 constants 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 constants or quantities.

See all constants alternatives → · See all quantities alternatives →

Recent activity from constants and quantities

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

  1. 1y agoquantitiesFixes covariance and correlation implementations
  2. 2y agoquantitiesFaster data.frame methods
  3. 3y agoquantitiesTest fixes for an upstream units change
  4. 3y agoquantitiesUncertainty becomes unit-aware; adds correlation support
  5. 5y agoconstantsCompatibility fix for units 0.7-0
  6. 5y agoquantitiesCompatibility fix for units 0.7-0
  7. 5y agoconstantsconstants 1.0.0
  8. 6y agoquantitiesFixes uncertainty propagation for offset unit conversions
  9. 8y agoconstantsUnit handling fixes ahead of the 1.0.0 rebuild

Frequently asked questions

What is the difference between constants and quantities?

Both compete on the same themes — units — within Analytics. constants 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 constants better than quantities?

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

Top constants alternatives in Analytics are ranked by recent ship velocity. Browse the "constants alternatives" section above for the current picks, or visit /alternatives/constants-r 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.