addMapLegendBoxes
From rworldmap v1.3-6
by Andy South
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
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)))
Community examples
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