AddScaleBar: Add Scale Bar to Plot

In USGS-R/inlmisc: Miscellaneous Functions for the USGS INL Project Office

Add Scale Bar to Plot

Description

Add a scale bar (also known as a rake scale) to a plot.

Usage

AddScaleBar(
  unit = NULL,
  conv.fact = NULL,
  vert.exag = NULL,
  longlat = FALSE,
  loc = "bottomleft",
  ...
)

Arguments

unit	'character' vector of length 1 or 2, value is recycled as necessary. Label(s) describing the unit of measurement of scale distances, such as "METERS".
conv.fact	'numeric' vector of length 1 or 2, value is recycled as necessary. Conversion factor(s) for changing the unit of measurement for scale distances. For example, if user coordinates of the plotting region are in meters, specify 3.28084 to display scale distances in feet. A dual-unit scale bar is created by specifying a second conversion factor.
vert.exag	'logical' flag, 'numeric' vector, or 'character' vector. Either a logical value indicating whether to include a vertical exaggeration label; or a custom y/x aspect ratio to include in this label.
longlat	'logical' flag. Whether user coordinates of the plotting region are in longitude and latitude; if true, scale distances are in kilometers. Scale distances are calculated at the maps latitude midpoint using the Great Circle distance (WGS84 ellipsoid) method.
loc	'character' string. Position of the scale bar in the main plot region; see GetInsetLocation function for keyword descriptions.
...	Additional arguments to be passed to the GetInsetLocation function—used to position the scale bar in the main plot region.

Value

Invisible NULL

Author(s)

J.C. Fisher, U.S. Geological Survey, Idaho Water Science Center

See Also

PlotMap, PlotCrossSection

Examples

plot(-100:100, -100:100, type = "n", xlab = "x in meters",
     ylab = "y in meters", asp = 2)
AddScaleBar()
AddScaleBar(loc = "center")
AddScaleBar(unit = "METERS", loc = "topleft", padin = 0.2)
AddScaleBar(unit = c("METERS", "FEET"), conv.fact = c(1, 3.28084),
            loc = "topright", padin = c(0.5, 0))
AddScaleBar(unit = c("METERS", "FEET"), conv.fact = c(1, 3.28084),
            vert.exag = TRUE, loc = "bottomright", inset = 0.1)

plot(c(-38.31, -35.5), c(40.96, 37.5), type = "n",
     xlab = "longitude", ylab = "latitude")
AddScaleBar(unit = "KILOMETERS", longlat = TRUE)
AddScaleBar(unit = "MILES", conv.fact = 0.621371, longlat = TRUE,
            loc = "topright", padin = c(0.4, 0))
AddScaleBar(unit = c("KILOMETERS", "MILES"),
            conv.fact = c(1, 0.621371), longlat = TRUE,
            loc = "topleft", inset = 0.05)

USGS-R/inlmisc documentation built on Sept. 17, 2022, 2:38 a.m.