pieSymbols: Produce pie charts at specified locations on a map

In ahb108/sparch: Assorted methods to supplement core spatial packages in R

Description

This function draw a pie chart at specified locations on a map.

Usage

pieSymbols(
  x,
  y,
  values,
  sizes = NULL,
  edges = 360,
  clockwise = FALSE,
  init.angle = if (clockwise) 90 else 0,
  density = NULL,
  angle = 45,
  col = NULL,
  border = NULL,
  lty = NULL,
  main = NULL,
  ...
)

Arguments

x	x coordinate of where the pie will be plotted
y	y coordinate of where the pie will be plotted
values	the values that will become the percentages of the pie.
sizes	the size of each pie.
edges	the number of increments used to describe the circle of the pie.
clockwise	whether the divisions are in clockwise order.
init.angle	where the pie starts te divisions
col	pie colors (length must be the same as ncol values)
border	border color(s) of the pies
...	passed to default plot function

Examples

data(SainteMarie85)
grains$SymSizes <- grains$SiloCount*8 #specify symbol sizes in map units
plotmat <- arrangeSymbols(grains, grains$SymSizes) #alternative pie locations
flines <- flylines(coordinates(grains)[,1],coordinates(grains)[,2],plotmat[,1],plotmat[,2]) #fly-lines from real locations to pie locations.
plot(boghar, col="grey75", border=NA, axes=TRUE, main="Barley (brown) and wheat (yellow)\nin 19th grain silos (Boghar, Algeria)") #background map
lines(flines, lwd=0.5) #fly-lines
pieSymbols(x=plotmat[,1], y=plotmat[,2], values=grains@data[,c("BarleyHL","WheatHL")], sizes=grains$SymSizes, col=c("saddlebrown","yellow")) #pies
points(grains, pch=19, cex=0.3, col="black") #real locations

ahb108/sparch documentation built on Feb. 3, 2021, 1:21 a.m.