NEWS

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ISO6976.2016 0.1-0 (2026-04-09)

Initial release — clean-room implementation of ISO 6976:2016 for CRAN.

Scope

Implements all properties and uncertainties defined in ISO 6976:2016:

• Compression factor Z (§5, Eq. 1)
• Molar mass M (Eq. 5)
• Ideal-gas and real-gas gross and net calorific values on molar, mass, and volumetric bases (Eqs. 2–12)
• Ideal-gas and real-gas density and relative density (Eqs. 13–19)
• Ideal-gas and real-gas gross and net Wobbe indices (Eqs. 15–16, 20–21)
• Standard uncertainties of all properties (Annex B, Eqs. B.4–B.14)

Design decisions

• Single Rcpp back-end (iso6976_calc) computes all properties in one call.
• GasComponents R6 class provides named component access without normalization (normalization is outside the scope of ISO 6976:2016).
• Component names are in English following ISO 6976:2016 Table A.2.
• Reference data sets example1, example2, example3, example3_ex are the worked examples from ISO 6976:2016 Annex D.