Odum ESL vertex helpers — odum

Low-level tibble-returning functions that compute polygon vertices for each of H.T. Odum's Energy Systems Language (ESL) symbols. Used internally by the geom_odum_source() family; also exported for users who want to hand-compose ggplot2::geom_polygon() layers, animate with gganimate, or render outside ggplot2.

Two inputs enter the flat left edge, one output exits the pointed right. Odum's canonical "multiplicative junction" symbol — distinctly NOT a diamond (that shape is a switch in Odum's ESL).

Odum's autocatalytic-unit symbol. Same silhouette as storage rotated 90° right: flat left edge, straight top+bottom, semi-circular right end.

Odum's on/off logic gate. Two triangles meeting at a central point, bounding-box (w, h).

Odum's "self-limited" unit — represents a producer/consumer whose output saturates.

Returns a data.frame with TWO groups: the down-arrow polygon and the horizontal ground line as a separate row-set (id column distinguishes them). Users can render together with a single geom_polygon + geom_segment, or use geom_odum_heat_sink() which wraps both.

Money flows in the opposite direction of energy in Odum's ESL, so this symbol is drawn with a dashed connection to the transacting unit. The returned tibble is the diamond body; the caller adds a geom_segment(linetype="dashed") for the flow line and a text label for "$".

Wikipedia's chart shows this as a lone right-pointing arrow. This helper returns the arrow polygon (shaft + triangular head) for drawing with geom_polygon; use geom_odum_flow() to add it inside a ggplot pipeline.

Usage

odum_circle(cx, cy, r, id, n = 60)

odum_source(cx, cy, r, id, n = 60)

odum_storage(cx, cy, w, h, id, n = 20)

odum_consumer(cx, cy, w, h, id)

odum_interaction(cx, cy, w, h, id)

odum_producer(cx, cy, w, h, id, n = 20)

odum_switch(cx, cy, w, h, id)

odum_self_limiter(cx, cy, w, h, id, n = 30)

odum_heat_sink(cx, cy, w, h, id)

odum_transaction(cx, cy, w, h, id)

odum_money(cx, cy, r, id, n = 60)

odum_flow(cx, cy, w, h, id)

Arguments

cx, cy: Numeric centre of the symbol.
r: Radius (for odum_circle() / odum_money()).
id: Group id (used as the group aesthetic in geom_polygon()).
n: Number of vertices to sample along curved arcs.
w, h: Width and height of the bounding rectangle.

Value

A tibble with columns x, y, id. For odum_transaction() a second tibble of dashed-flow line coordinates is returned in the "flow" attribute.

Details

Geometry follows Wikipedia's canonical reference chart (https://commons.wikimedia.org/wiki/File:Energese.jpg).

Examples

library(ggplot2)

# Each helper returns a vertex tibble that geom_polygon() draws.

# Circle (source, money) — parameterised by centre + radius
verts <- odum_circle(cx = 0, cy = 0, r = 0.5, id = 1)
ggplot(verts, aes(x, y, group = id)) +
  geom_polygon(fill = "#F1C40F", colour = "black") +
  coord_fixed() + theme_void()


# Bertalanffy storage
ggplot(odum_storage(0, 0, 1, 0.8, id = 1),
       aes(x, y, group = id)) +
  geom_polygon(fill = "#1F77B4", colour = "black") +
  coord_fixed() + theme_void()


# Hexagonal consumer
ggplot(odum_consumer(0, 0, 1, 0.9, id = 1),
       aes(x, y, group = id)) +
  geom_polygon(fill = "#C0392B", colour = "black") +
  coord_fixed() + theme_void()


# Chevron interaction
ggplot(odum_interaction(0, 0, 1, 0.8, id = 1),
       aes(x, y, group = id)) +
  geom_polygon(fill = "#F39C12", colour = "black") +
  coord_fixed() + theme_void()


# Bullet producer
ggplot(odum_producer(0, 0, 1.2, 0.8, id = 1),
       aes(x, y, group = id)) +
  geom_polygon(fill = "#2E7D32", colour = "black") +
  coord_fixed() + theme_void()


# Bowtie switch — two triangles emitted as distinct groups
ggplot(odum_switch(0, 0, 1, 0.8, id = 1),
       aes(x, y, group = id)) +
  geom_polygon(fill = "#607D8B", colour = "black") +
  coord_fixed() + theme_void()


# Semi-circular self-limiter
ggplot(odum_self_limiter(0, 0, 0.8, 0.8, id = 1),
       aes(x, y, group = id)) +
  geom_polygon(fill = "#c62828", colour = "black") +
  coord_fixed() + theme_void()


# Heat sink (down-arrow + ground line — multi-group)
ggplot(odum_heat_sink(0, 0, 0.6, 0.9, id = 1),
       aes(x, y, group = id)) +
  geom_polygon(fill = "#455a64", colour = "black") +
  coord_fixed() + theme_void()


# Elongated diamond transaction
ggplot(odum_transaction(0, 0, 1.4, 0.5, id = 1),
       aes(x, y, group = id)) +
  geom_polygon(fill = "#b5791b", colour = "black") +
  coord_fixed() + theme_void()


# Bare-arrow flow
ggplot(odum_flow(0, 0, 1.2, 0.5, id = 1),
       aes(x, y, group = id)) +
  geom_polygon(fill = "grey30", colour = "black") +
  coord_fixed() + theme_void()


# Compose several helpers by rbind()-ing vertex tibbles.
verts <- rbind(
  transform(odum_source  (1, 0, 0.3, id = 1), role = "source"),
  transform(odum_producer(3, 0, 0.8, 0.6, id = 2), role = "producer"),
  transform(odum_consumer(5, 0, 0.8, 0.6, id = 3), role = "consumer"))
ggplot(verts, aes(x, y, group = id, fill = role)) +
  geom_polygon(colour = "black") +
  coord_fixed() + theme_void() +
  scale_fill_manual(values = c(source = "#F1C40F",
                               producer = "#2E7D32",
                               consumer = "#8B4513"))