energese: ggplot2 Layers for H.T. Odum's Energy Systems Language

Details

Provides grammar-of-graphics ggplot2 layers for H.T. Odum's Energy Systems Language (ESL) — also known as Energese, Energy Circuit Language, or Generic Systems Symbols. Odum developed the language in the 1950s during tropical-forest studies at El Verde, Puerto Rico (Odum & Pigeon 1970, funded by the U.S. Atomic Energy Commission).

Every canonical symbol on Wikipedia's Energese reference chart (https://commons.wikimedia.org/wiki/File:Energese.jpg) is exposed:

• geom_odum_source() — circle (renewable / external input)

• geom_odum_flow() — bare arrow (generic flow)

• geom_odum_storage() — Bertalanffy module

• geom_odum_consumer() — hexagon (consumer)

• geom_odum_interaction() — chevron (multiplicative junction)

• geom_odum_producer() — bullet (autocatalytic producer)

• geom_odum_switch() — bowtie (logic gate)

• geom_odum_self_limiter() — semi-circle (saturating unit)

• geom_odum_heat_sink() — down-arrow + ground line (heat sink)

• geom_odum_transaction() — elongated diamond (money transaction)

See plot_energese_reference() for a single function that reproduces Wikipedia's canonical chart.

Two APIs are exposed:

• High-level (recommended) — the ggplot2 Geoms above, with standard aesthetics. Vectorised over data rows; composable in a ggplot() pipeline like any other ggplot2 layer.

• Low-level — vertex-tibble helpers (odum_symbols) that return (x, y, id) coordinates suitable for ggplot2::geom_polygon(). Use these when you want to hand-compose polygons, animate with gganimate, or render outside ggplot2.

Prior art

To the author's knowledge, energese is the first R (or Python) grammar-of-graphics library for ESL. The closest peers are the now-abandoned Java EmSim (an ODE integrator, no rendering API), the TypeScript GUI editor https://github.com/sholtomaud/odum-energy-language (Sholto Maud, who also produced the Visio stencil that Wikipedia's Energese chart is based on), and static SVG reference libraries from the UF Center for Environmental Policy. See the vignette (vignette("energese")) for a full worked example and prior-art scan.

References

• Odum, H.T. & Pigeon, R.F. (eds.) (1970). A Tropical Rain Forest: A Study of Irradiation and Ecology at El Verde, Puerto Rico.

• Odum, H.T. (1994). Ecological and General Systems: An Introduction to Systems Ecology. Rev. ed.

• Odum, H.T. & Odum, E.C. (2000). Modeling for All Scales.

• Odum, H.T. (2007). Environment, Power, and Society for the Twenty-First Century: The Hierarchy of Energy.

• Brown, M.T. (2004). "A picture is worth a thousand words: energy systems language and simulation." Ecological Modelling 178: 83-100. doi:10.1016/j.ecolmodel.2003.12.008

See also

The Wikipedia article on Energy Systems Language.

Author

Maintainer: Eric Scheier hello@emrgi.com