auto.shading: auto.shading

In GISTools: Further Capabilities in Geographic Information Science

auto.shading

Description

Creates an object of class shading automatically, given a choropleth variable to be mapped.

Usage

auto.shading(x, digits = 2, cutter = quantileCuts, n = 5, 
	params = NA, cols = brewer.pal(n, "Reds"))

Arguments

x	The variable to be mapped.
digits	The number of significant digits to round the class limits to.
cutter	Function used to create the break points. Can be user defined or a supplied cut function.
n	The number of classes. The should be one more than the number of break points.
params	Other parameters to be passed to the cut function.
cols	List of colours for shading each class. length(cols) should be equal to n.

Details

Returns an object of class shading, as set out below:

Value

An object of class shading, having the following list elements:

breaks	Break points between choropleth classes. length(cols)
cols	Colours to shade in each class. length(cols) should be one more than length(breaks)

Author(s)

Chris Brunsdon, Binbin Lu

See Also

choropleth,shading,choro.legend.

Examples

# Read in map data and compute a rate for mapping
# Try the sf class
data(WHData)
shades = auto.shading(WHHP[["Avg_HP_avg"]],n=7)
dev.new(width = 16, height = 12)
choropleth(sp = WHHP,v="Avg_HP_avg",shading=shades)
choro.legend(548871.4, 3377000, shades,title='Average house price')
#Try the Spatial object
shades = auto.shading(whp_sp@data[["Avg_HP_avg"]],n=6)
dev.new(width = 16, height = 12)
choropleth(sp = whp_sp,v="Avg_HP_avg",shading=shades)
choro.legend(548871.4, 3377000,  shades,title='Average house price')

GISTools documentation built on Oct. 3, 2024, 1:08 a.m.