oce (version 1.8-2)

mapCoordinateSystem: Draw a Coordinate System

Description

Draws arrows on a map to indicate a coordinate system, e.g. for an to indicate a coordinate system set up so that one axis is parallel to a coastline.

Usage

mapCoordinateSystem(longitude, latitude, L = 100, phi = 0, ...)

Arguments

longitude

numeric vector of longitudes in degrees.

latitude

numeric vector of latitudes in degrees.

L

axis length in km.

phi

angle, in degrees counterclockwise, that the "x" axis makes to a line of latitude.

...

plotting arguments, passed to mapArrows(); see “Examples” for how to control the arrow-head size.

Sample of Usage

library(oce)
if (requireNamespace("ocedata", quietly=TRUE)) {
    data(coastlineWorldFine, package="ocedata")
    HfxLon <- -63.5752
    HfxLat <- 44.6488
    mapPlot(coastlineWorldFine, proj="+proj=merc",
        longitudelim=HfxLon+c(-2,2), latitudelim=HfxLat+c(-2,2),
        col=lightgrey")
    mapCoordinateSystem(HfxLon, HfxLat, phi=45, length=0.05)
   }

Author

Chantelle Layton

Details

This is a preliminary version of this function. It only works if the lines of constant latitude are horizontal on the plot.

See Also

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