mapContour {oce} | R Documentation

## Add Contours on a Existing map

### Description

Plot contours on an existing map.

### Usage

    mapContour(longitude = seq(0, 1, length.out = nrow(z)), latitude = seq(0, 1,
      length.out = ncol(z)), z, nlevels = 10, levels = pretty(range(z, na.rm =
      TRUE), nlevels), col = par("fg"), lty = par("lty"), lwd = par("lwd"))

### Arguments

`longitude` | vector of longitudes of points to be plotted, or an object of class `topo` (see `topo-class`), in which case `longitude`, `latitude` and `z` are inferred from that object.
`latitude` | vector of latitudes of points to be plotted.
`z` | matrix to be contoured.
`nlevels` | number of contour levels, if and only if `levels` is not supplied.
`levels` | vector of contour levels.
`col` | line colour.
`lty` | line type.
`lwd` | line width.

### Details

Adds contour lines to an existing map, using `mapLines`. The arguments are based on those to `contour` and `contourLines`.

### Bugs

As with `mapLines`, long lines should be subdivided into multiple segments so that e.g. great circle lines will be curved.

### Author(s)

Dan Kelley

### See Also

A map must first have been created with `mapPlot`.

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

### Examples

    ## Not run:
    library(oce)
    data(coastlineWorld)
    par(mar=rep(1, 4))
    ## Arctic 100m, 2km, 3km isobaths, showing shelves and ridges.
    mapPlot(coastlineWorld, latitudelim=c(60, 120), longitudelim=c(-130,-50),
            projection="+proj=stere +lat_0=90")
    data(topoWorld)
    lon <- topoWorld[['longitude']]
    lat <- topoWorld[['latitude']]
    z <- topoWorld[['z']]
    mapContour(lon, lat, z, levels=c(-100, -2000, -3000), col=1:3, lwd=2)

    ## End(Not run)

[Package oce version 0.9-22 Index]