Add Arrows to a Map

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

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 color, passed to arrows().

lty

arrow line type, passed to arrows().

lwd

arrow line width, passed to arrows().

...

optional arguments passed to arrows().

See also

A map must first have been created with mapPlot().

Other functions related to maps: formatPosition(), lonlat2map(), lonlat2utm(), map2lonlat(), mapAxis(), mapContour(), mapCoordinateSystem(), mapDirectionField(), mapGrid(), mapImage(), mapLines(), mapLocator(), mapLongitudeLatitudeXY(), mapPlot(), mapPoints(), mapPolygon(), mapScalebar(), mapText(), mapTissot(), oceCRS(), oceProject(), shiftLongitude(), usrLonLat(), utm2lonlat()

Author

Dan Kelley

Examples

# \donttest{
library(oce)
data(coastlineWorld)
mapPlot(coastlineWorld,
    longitudelim = c(-120, -60), latitudelim = c(30, 60),
    col = "lightgray", projection = "+proj=lcc +lat_1=45 +lon_0=-100"
)
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")

# }