View source: R/addRasterLegend.R
addRasterLegend | R Documentation |
Adds a legend to an existing raster plot, with some additional manual control
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 = "", ... )
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 |
side |
side for tick marks, see |
location |
either a location name (see |
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 |
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 |
locs |
locations of tick marks, if |
cex.axis |
size of axis labels |
labelDist |
distance from axis to axis labels (passed to |
digits |
number of decimal places for labels |
bigmark |
character used to separate thousands and millions, passed
to |
... |
additional parameters to be passed to |
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.
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.
Pascal Title
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