oce (version 0.9-18)

mapArrows: Plot arrows on a existing map

Description

Plot arrows on an existing map, e.g. to indicate a place location. This is not well-suited for drawing direction fields, e.g. of velocities; for that, see mapDirectionField.

Usage

mapArrows(longitude0, latitude0,
                      longitude1=longitude0, latitude1=latitude0,
                      length=0.25, angle=30,
                      code=2, col=par("fg"), lty=par("lty"),
                      lwd=par("lwd"), ...)

Arguments

longitude0, latitude0

starting points for arrows

longitude1, latitude1

ending points for arrows

length

length of the arrow heads, passed to arrows

angle

angle of the arrow heads, passed to arrows

code

numerical code indicating the type of arrows, passed to arrows

col

arrow colour, passed to arrows

lty

arrow line type, passed to arrows

lwd

arrow line width, passed to arrows

...

optional arguments passed to arrows

Details

Adds arrows to an existing map, by analogy to arrows.

See Also

See mapPlot for general information on plotting maps, including other functions.

Examples

library(oce)
data(coastlineWorld)
mapPlot(coastlineWorld, longitudelim=c(-130,-55), latitudelim=c(35,60),
        proj="lambert", parameters=c(lat0=40,lat1=60),
        orientation=c(90,-100,0))
lon <- seq(-120, -75, 15)
n <- length(lon)
lat <- 45 + rep(0, n)
# Draw meridional arrows in N America, from 45N to 60N.
mapArrows(lon, lat, lon, lat+15, length=0.05, col="blue")