maplegend (version 0.5.0)

leg_comp: Compose a map legend

Description

Compose a map legend with several elements. The "type" argument defines the legend type. Please note that some arguments are available for all types of legend and some others are only relevant for specific legend types.

Usage

leg_comp(
  leg,
  type,
  val,
  pal = "Inferno",
  alpha = NULL,
  col = "tomato4",
  inches = 0.3,
  symbol = "circle",
  self_adjust = FALSE,
  lwd = 0.7,
  border = "#333333",
  pch = 1:seq_along(val),
  cex = rep(1, length(val)),
  title = "Legend Title",
  val_rnd = 0,
  val_dec = ".",
  val_big = "",
  col_na = "white",
  cex_na = 1,
  pch_na = 4,
  no_data = FALSE,
  no_data_txt = "No Data",
  box_border = "333333",
  box_cex = c(1, 1),
  horiz = FALSE
)

Value

A list of legends parameters is returned.

Arguments

leg

legend object

type

type of legend:

• prop for proportional symbols,

• choro for choropleth maps,

• cont for continuous maps (e.g. raster),

• typo for typology maps,

• symb for symbols maps,

• prop_line for proportional lines maps,

• grad_line for graduated lines maps,

• histo for histograms.

val

vector of value(s) (for "prop" and "prop_line", at least c(min, max) for "cont"), vector of categories (for "symb" and "typo"), break labels (for "choro" and "grad_line"), histogram parameters (for "histo").

pal

a color palette name or a vector of colors

alpha

opacity, in the range [0,1]

col

color of the symbols (for "prop") or color of the lines (for "prop_line" and "grad_line")

inches

size of the largest symbol (radius for circles, half width for squares) in inches

symbol

type of symbols, 'circle' or 'square'

self_adjust

if TRUE values are self-adjusted to keep min, max and intermediate rounded values

lwd

width(s) of the symbols borders (for "prop" and "symb"), width of the largest line (for "prop_line"), vector of line width (for "grad_line")

border

symbol border color(s)

pch

type(s) of the symbols (0:25)

cex

size(s) of the symbols

title

title of the legend

val_rnd

number of decimal places of the values in the legend

val_dec

decimal separator

val_big

thousands separator

col_na

color for missing values

cex_na

size of the symbols for missing values

pch_na

type of the symbols for missing values

no_data

if TRUE a "missing value" box is plotted

no_data_txt

label for missing values

box_border

border color of legend boxes

box_cex

width and height size expansion for boxes, histogram or lines

horiz

if TRUE plot an horizontal legend

Examples

# minimal example
plot.new()
plot.window(xlim = c(0, 1), ylim = c(0, 1), asp = 1)
box()
leg_comp(type = "prop", val = c(10, 50, 100)) |>
  leg_comp(type = "typo", val = c("A", "B", "C")) |>
  leg_draw()