read.coastline cannot read a file, or
when the data have been manipulated.
as.coastline(longitude, latitude, fillable = FALSE)latitude and
longitude, in which case these values are extracted from the data
frame and the second argument is ignored.class "coastline" (for
details, see read.coastline).
coastline data: [[,coastline-method,
[[<-,coastline-method,
coastline-class,
coastlineBest, coastlineCut,
coastlineWorld,
download.coastline,
plot,coastline-method,
read.coastline.openstreetmap,
read.coastline.shapefile,
subset,coastline-method,
summary,coastline-method