R: Draw a coordinate system

mapCoordinateSystem {oce} | R Documentation

## 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 value of longitude in degrees.
`latitude` | numeric value of latitude 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.

### Details

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

### Author(s)

Chantelle Layton

### 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()`

### Examples

    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)
       }

[Package oce version 1.2-0 Index]