mapPies: function to produce pie charts on a map

In rworldmap: Mapping Global Data

function to produce pie charts on a map

Description

The function will produce a map with pie charts centred on country centroids (or other chosen points). The size of the circles is determined by the sum of the attribute columns and each section is coloured.

Usage

mapPies(
  dF,
  nameX = "LON",
  nameY = "LAT",
  nameZs = c(names(dF)[3], names(dF)[4]),
  zColours = c(1:length(nameZs)),
  ratio = 1,
  addCatLegend = TRUE,
  symbolSize = 1,
  maxZVal = NA,
  xlim = NA,
  ylim = NA,
  mapRegion = "world",
  borderCol = "grey",
  oceanCol = NA,
  landCol = NA,
  add = FALSE,
  main = "",
  lwd = 0.5,
  ...
)

Arguments

dF	data frame or SpatialPolygonsDataFrame
nameX	name of column containing the X variable (longitude), not needed if dF is a SpatialPolygonsDataFrame
nameY	name of column containing the Y variable (latitude), not needed if dF is a SpatialPolygonsDataFrame
nameZs	name of columns containing numeric variables to determine pie sections
zColours	colours to apply to the pie section for each attribute column
ratio	the ratio of Y to N in the output map, set to 1 as default
addCatLegend	whether to add a legend for categories
symbolSize	multiplier of default symbol size
maxZVal	the attribute value corresponding to the maximum symbol size, this can be used to set the scaling the same between multiple plots
xlim	map extents c(west,east), can be overidden by mapRegion
ylim	map extents c(south,north), can be overidden by mapRegion
mapRegion	a country name from getMap()[['NAME']] or 'world','africa','oceania','eurasia','uk' sets map extents, overrides xlim,ylim
borderCol	the colour for country borders
oceanCol	a colour for the ocean
landCol	a colour to fill countries
add	whether to add the symbols to an existing map, TRUE/FALSE
main	title for the map
lwd	line width for country borders
...	any extra arguments to points()

Details

Beware of creating plots that are difficult for the reader to interpret. More than 3 or 4 categories may be too many.

Value

currently doesn't return anything

Author(s)

andy south

Examples

#getting example data
dF <- getMap()@data  

## these examples repeat the same column in 'nameZs' 
## to show that equal sized pies are created  

#mapPies( dF,nameX="LON", nameY="LAT",nameZs=c('AREA','AREA') )

#mapPies( dF,nameX="LON", nameY="LAT",nameZs=c('AREA','AREA')
#       , mapRegion='africa' )

mapPies( dF,nameX="LON", nameY="LAT"
       , nameZs=c('POP_EST','POP_EST','POP_EST','POP_EST'),mapRegion='africa' )
  

rworldmap documentation built on Oct. 16, 2023, 5:07 p.m.