gisimage: Display a color image.

In phiala/giscolor: Provides GRASS 7.0 color tables for plotting GIS data in R

Description

Displays a grid-like colored image using color values from a GIS color palette.

Usage

gisimage(x, pal, attr = 1, plot = TRUE, legend = TRUE, ...)

Arguments

x	A grid-like data object, including matrix, data frame, or SpatialGridDataFrame.
pal	A GIS palette.
attr	If x is a SpatialGridDataFrame, can specify which value to use by position or name.
plot	If FALSE, the image is not displayed.
legend	If TRUE, a legend is added to the plot.
...	Other arguments to be passed to image().

Details

This function enables the use of color palettes from GRASS GIS to display GIS images within R. A percentage-based palette is automatically expanded to match the range of values in x. If a different range is desired, gis.pal can be used to set up the palette before plotting.

Value

The binned dataset matching the levels of the palette is returned invisibly.

Author(s)

Sarah Goslee

References

The palettes included are adapted from the GRASS 7.0 color tables https://grasswiki.osgeo.org/wiki/Color_tableshttps://grasswiki.osgeo.org/wiki/Color_tables.

See Also

codeimage, codegis.pal, codegis.pal.info,

Examples

# generate sample data
mat1 <- matrix(runif(100), 10, 10)
# expand an included GIS palette to 11 colors
pal1 <- gis.pal("gyr", n=11, zlim=c(0,1))
pal1
# display the image and a color ramp
## Not run: 
layout(matrix(c(1,1,1,2), ncol=1))
gisimage(mat1, pal1, legend=FALSE)
display.gis.pal(pal=pal1)

## End(Not run)

# create a new palette
# note that palettes do not have to be regular
pal2 <- read.gis.pal(text = "
	0 black
	10
	20
	100
	")

## Not run: 
layout(matrix(c(1,1,1,2), ncol=1))
# A percentage-based palette is automatically expanded.
gisimage(mat1, pal2, legend=FALSE)
display.gis.pal(pal=pal2)

## End(Not run)

phiala/giscolor documentation built on Jan. 28, 2020, 3:35 a.m.