mapspot: Draw map and add bubbles
In seancarmody/rmapaus: Australian map data and tools

Use ggplot2 to draw a map and fill regions of the map based on values in a dataframe.

mapspot(x, map, fill, size, id = intersect(names(x), names(map)),
  id.name = id, border = "grey95", ticks = FALSE, labels = FALSE,
  label.filter = TRUE, lab.size = 3, regions = "white", max_size = 6,
  size.label = comma, ...)

`x`	data frame with fill values and bubble sizes
`map`	a map of type `SpatialPolygonsDataFrame`
`fill`	name of field in `x` containing fill values
`size`	name of field in `x` containing the size values (mapped to size aesthetic).
`id`	name of field in `x` containing map region id values. Defaults to the first field name `x` and `map` have in common
`id.name`	name of field in `mapdata` containing region names used for (optional) region labelling
`border`	colour of region borders
`ticks`	a logical value indicating whether tick marks should be added to axes. Defaults to `FALSE`.
`labels`	a logical value indicating whether regions should be labelled. Defaults to `FALSE`
`label.filter`	string to be evaluated in the context of 'x' which determines whether a given region will be labelled.
`lab.size`	size of region label text
`regions`	colour of map regions
`max_size`	maximum size of bubbles
`size.label`	label formatter defaults to `comma`
`...`	additional parameters passed to `geom_text`