mapArrows: Add Arrows to a Map

In oce: Analysis of Oceanographic Data

Add Arrows to a 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(). 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().

Author(s)

Dan Kelley

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(), shiftLongitude(), usrLonLat(), utm2lonlat()

Examples

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")

oce documentation built on July 9, 2023, 5:18 p.m.