HelpersMG (version 5.1)

newmap.scale: Add Scale to Existing Unprojected Map

Description

Adds a scale to an existing map, both as a ratio and a distance gauge. If x or y are not specified, this will be taken to be near the lower left corner of the map.

Usage

newmap.scale(
  x,
  y,
  relwidth = 0.15,
  metric = TRUE,
  ratio = TRUE,
  col.line = "black",
  ...
)

Arguments

x

Location of left end of distance gauge.

y

Location of left end of distance gauge.

relwidth

Proportion of width of display to be used for the scale. The default is 0.15.

metric

If TRUE, the distance gauge will be in km, otherwise miles.

ratio

If FALSE, the scale ratio of the map is not displayed.

col.line

The color of lines for the gauge.

...

Further plotting parameters may be specified as for the command text().

Value

The exact calculated scale is returned.

Details

newmap.scale Add Scale to Existing Unprojected Map

Examples

# NOT RUN {
library("maps")
library("HelpersMG")
map("world", "China")
newmap.scale(col.line = "red", col="blue")
# }