Easily turn data from the maps package in to a data frame suitable for plotting with ggplot2.
map_data(map, region = ".", exact = FALSE, ...)
name of map provided by the maps package. These
include maps::county()
, maps::france()
,
maps::italy()
, maps::nz()
,
maps::state()
, maps::usa()
,
maps::world()
, maps::world2()
.
name of subregions to include. Defaults to .
which
includes all subregion. See documentation for maps::map()
for more details.
should the region
be treated as a regular expression
(FALSE
) or as a fixed string (TRUE
).
all other arguments passed on to maps::map()
# NOT RUN { if (require("maps")) { states <- map_data("state") arrests <- USArrests names(arrests) <- tolower(names(arrests)) arrests$region <- tolower(rownames(USArrests)) choro <- merge(states, arrests, sort = FALSE, by = "region") choro <- choro[order(choro$order), ] ggplot(choro, aes(long, lat)) + geom_polygon(aes(group = group, fill = assault)) + coord_map("albers", at0 = 45.5, lat1 = 29.5) ggplot(choro, aes(long, lat)) + geom_polygon(aes(group = group, fill = assault / murder)) + coord_map("albers", at0 = 45.5, lat1 = 29.5) } # }
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