projectedmap: Return a projected map with given extent

In jarioksa/biogeo: Tools for Biogeography Lectures

Description

The function takes either limits of extent or a two-column matrix and returns a projected map containing the original limits or the points.

Usage

projectedmap(extent, CRS = "+proj=longlat +datum=WGS84",
  inCRS = "+proj=longlat +datum=WGS84", resolution = "low", pad = 0.04,
  ...)

Arguments

extent	Either (1) a four element numeric vector of east min, east max, north min, north max or (2) a two-column matrix of coordinates of points that should be shown on the map, or (3) a species occurence data from occ (spocc package).
CRS	CRS string defining the output projection.
inCRS	CRS string describing the input projection of extent. This will not be used if CRS is already defined for the extent.
resolution	Resolution of the map as defined in getMap.
pad	extend climits by this proportion of coordinate range.
...	Other arguments passed to the function (ignored).

Examples

## Lambert Azimuthal Equal Area: EU recommendation
pl <-projectedmap(c(5,31,54,71), CRS="+init=epsg:3035", pad=0)
plot(pl, col="gray")
## display extent defined by latitude and longitude ranges
llgridlines(pl, east=c(5,31), north=c(54,71), lty=1)

## Research areas in Virtanen et al., J. Veg. Sci. 17, 519-528 (2006)
sites <- structure(list(lon = c(41, 46, 50, 54, 67, 70, 102, 
112, 117, 141, 142, 149, 163, 179, 16, 138), lat =
c(67.3, 68.15, 69.15, 68.5, 70.45, 73, 77.2, 76, 73, 72, 75, 71, 69,
71, 78, 75)), .Names = c("longit", "latid"), row.names = c("Kack",
"Kani", "Kolg", "Pech", "WYam", "NYam", "Chel",
"Neta", "Olon", "Yana", "Fadd", "Lopa", "Koly",
"Wran", "Sval", "Kote"), class = "data.frame")
## LAEA North Pole Russia -- default padding will extend the area to an
## illegal polygon
pl <- projectedmap(sites, CRS= "+init=epsg:3576", pad=0)
plot(pl)
points(attr(pl, "input"), pch=16, col=4)

jarioksa/biogeo documentation built on May 18, 2019, 3:47 p.m.