addMapLegendBoxes

0th

Percentile

Add a legend of coloured boxes to a map

Creates a colour box legend, showing the range of colours and the values the colours correspond to. This works well for categorical data with relatively few categories.

Keywords
aplot
Usage
addMapLegendBoxes(cutVector = "", colourVector = "", x = "bottomleft", horiz = FALSE, title = "category", cex = 1, pt.cex = 2, col = "gray", bg = "white", legendText = "", catMethod = "categorical", plottedData = "", colourPalette = "heat", sigFigs = 2, missingCountryCol = "white", ...)
Arguments
cutVector
the categories or breaks used in the map
colourVector
colours used in the map
x
positioning of legend e.g. 'bottomleft', 'topright'
horiz
if TRUE horizontal legend
title
title for Legend
cex
controls the font size, default is 1
pt.cex
controls size of colour boxes relative to cex, default is 2
col
colour for boundary of colour boxes, default is "gray"
bg
colour for legend background, default is "white", NA makes the legend background transparent
legendText
the text to put against each legend box, if left blank cutVector is used, needs to be a vector the same length as length cutVector
catMethod
the categorisation method used influences what text added to legend elements, for 'categorical' just the category names are used for other options limits are used
plottedData
not used yet but maybe in future
colourPalette
not used yet but maybe in future
sigFigs
not used yet but maybe in future
missingCountryCol
not used yet but maybe in future
...
to allow other params to be set in legend
Details

This creates a legend with separate boxes of colour rather than addMapLegend() which creates a colour bar. This method is used as the default for categorical data.

See the examples for how to use a parameter list returned from mapping functions.

Value

Adds a legend to a plot.

See Also

addMapLegend, mapCountryData, mapGriddedData

Aliases
  • addMapLegendBoxes
Examples

#Set up the plot so the world map uses the full width.
mapDevice() 
#map example categorical data with no legend              
mapParams <- mapCountryData(nameColumnToPlot='GEO3major'
              , catMethod='categorical'
              , addLegend='FALSE' 
              )
              
#add default legend using the same parameters as mapCountryData               
do.call( addMapLegendBoxes, c( mapParams))

#adding a modified legend by specifying extra parameters               
do.call( addMapLegendBoxes, c(mapParams,x='bottom',horiz=TRUE,title="Region"))

#user defined map colour sceme              
mapParams <- mapCountryData(nameColumnToPlot='GEO3major'
              , catMethod='categorical'
              , addLegend='FALSE'
              , colourPalette=c('white','green','red','yellow','blue','black') 
              )
#changing legendText
mapParams$legendText <- c('antarctic','africa','oceania'
                         ,'americas','s.asia','eurasia')              
do.call( addMapLegendBoxes, c(mapParams,x='bottom',title="Region",horiz=TRUE))

#or this way
#do.call( addMapLegendBoxes
#        , c(mapParams
#           ,list(legendText=c('antarctic','africa','oceania'
#                              ,'americas','s.asia','eurasia')
#                ,x='bottom',title="Region",horiz=TRUE)))



Documentation reproduced from package rworldmap, version 1.3-6, License: GPL (>= 2)

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