addRasterLegend: addRasterLegend

In rangeBuilder: Occurrence Filtering, Geographic Standardization and Generation of Species Range Polygons

addRasterLegend

Description

Adds a legend to an existing raster plot, with some additional manual control

Usage

addRasterLegend(
  r,
  direction,
  side,
  location = "right",
  nTicks = 2,
  adj = NULL,
  shortFrac = 0.02,
  longFrac = 0.3,
  axisOffset = 0,
  border = TRUE,
  ramp = "terrain",
  isInteger = "auto",
  ncolors = 64,
  breaks = NULL,
  minmax = NULL,
  locs = NULL,
  cex.axis = 0.8,
  labelDist = 0.7,
  digits = 2,
  bigmark = "",
  ...
)

Arguments

r	the rasterLayer object that has been plotted
direction	direction of color ramp. If omitted, then direction is automatically inferred, otherwise can be specified as horizontal or vertical.
side	side for tick marks, see axis documentation. Automatically inferred if omitted.
location	either a location name (see Details), or coordinates for the corners of the bar legend c(xmin, xmax, ymin, ymax).
nTicks	number of tick marks, besides min and max.
adj	if location is top, left, bottom or right, use this argument to adjust the location of the legend, defined in percent of the figure width. See Details for additional information.
shortFrac	Percent of the plot width range that will be used as the short dimention of the legend. Only applies to preset location options.
longFrac	Percent of the plot width range that will be used as the long dimention of the legend. Only applies to preset location options.
axisOffset	distance from color bar for labels, as a percent of the plot width.
border	logical, should the color legend have a black border
ramp	either a vector of color names for defining the color ramp, or "terrain" (default raster behavior)
isInteger	If auto, automatically determines if raster is made up of integer values, otherwise TRUE or FALSE
ncolors	grain size of color ramp
breaks	If a custom set of color breaks were used in plotting the raster, pass those color breaks here. This overrides the minmax option.
minmax	min and max values from which the color ramp will be derived. If left as NULL, the min and max of the raster will be used.
locs	locations of tick marks, if NULL automatically placed
cex.axis	size of axis labels
labelDist	distance from axis to axis labels (passed to mgp)
digits	number of decimal places for labels
bigmark	character used to separate thousands and millions, passed to format
...	additional parameters to be passed to axis.

Details

A number of predefined locations exist in this function to make it easy to add a legend to a raster plot. Preset locations are: topleft, topright, bottomleft, bottomright, left, right, top and bottom. If more fine-tuned control is desired, then a numeric vector of length 4 can be supplied to location, specifying the min x, max x, min y and max y values for the legend. Additionally, the adj argument can be used to more intuitively adjust where the legend is placed. adj is defined as a percentage of the figure width or height, left to right, or bottom to top, respectively. For example, if the legend is at the bottom, adj = 0.8 will place the legend 80 the figure, horizontally centered. See examples.

Value

Invisibly returns a list with the following components.

• coords2-column matrix of xy coordinates for each color bin in the legend.

• widthCoordinates for the short dimension of the legend.

• palthe color ramp

• tickLocsthe tick mark locations in plotting units

• labelsthe values associated with those tick locations.

Author(s)

Pascal Title

rangeBuilder documentation built on March 7, 2023, 5:30 p.m.