oce (version 0.9-13)

mapImage: Plot an image on a existing map

Description

Plot an image on an existing map

Usage

mapImage(longitude, latitude, z, zlim, zclip=FALSE, breaks, col,
         filledContour=FALSE, missingColor=NULL, debug=getOption("oceDebug"))

Arguments

longitude

longitudes of grid lines

latitude

latitudes of grid lines

z

matrix for image

zlim

limit for z (colour)

zclip

logical, indicating whether to clip the colours to those corresponding to zlim, if the latter is provided. Clipped regions will be coloured with missingColor.

breaks

the z values for breaks in the colour scheme. If this is of length 1, the value indicates the desired number of breaks, which is supplied to pretty, in determining clean break points.

col

either a vector of colours corresponding to the breaks, of length 1 plus the number of breaks, or a function specifying colours, e.g. oceColorsJet for a rainbow.

filledContour

boolean value indicating whether to use filled contours to plot the image.

missingColor

a color to be used to indicate missing data, or NULL to simply skip the drawing of such regions.

debug

a flag that turns on debugging. Set to 1 to get a moderate amount of debugging information, or to 2 to get more.

Details

Adds an image to an existing map, by analogy to image.

See Also

See mapPlot for general information on plotting maps, including other functions.

Examples

library(oce)
data(coastlineWorld)
mapPlot(coastlineWorld, type='l',
        latitudelim=c(40,50), longitudelim=c(-70,-50),
        proj="polyconic", orientation=c(90, -60,0), grid=TRUE)
data(topoWorld)
mapImage(topoWorld, col=oceColorsGebco)
mapMeridians(10, lty='dotted', col='darkgray')
mapZones(10, lty='dotted', col='darkgray')
mapLines(coastlineWorld)

## Northern polar region, with colour-coded bathymetry
drawPalette(c(-5000,0), zlim=c(-5000, 0), col=oceColorsJet)
mapPlot(coastlineWorld, type='l',
         latitudelim=c(60,120), longitudelim=c(-180,180),
         proj="stereographic", grid=TRUE)
data(topoWorld)
mapImage(topoWorld, zlim=c(-5000, 0), col=oceColorsJet)
mapMeridians()
mapZones()
mapLines(coastlineWorld[['longitude']], coastlineWorld[['latitude']])

# Levitus July SST (requires dataset from http://www.esrl.noaa.gov)
library(ncdf)
con <- open.ncdf("/data/oar/levitus/otemp.mnltm.nc")
lon <- get.var.ncdf(con, "lon")
lat <- get.var.ncdf(con, "lat")
SSTjuly <- get.var.ncdf(con, "otemp")[,,1,7]
x11(width=8, height=4) # x11 is fast, so use for tests
par(mar=rep(1, 4))
Tlim <- c(-2, 30)
drawPalette(Tlim, col=oceColorsJet)
mapPlot(coastlineWorld, projection='mollweide', grid=FALSE)
mapImage(lon, lat, SSTjuly, col=oceColorsJet, zlim=Tlim, missingColor='lightgray')
mapLines(coastlineWorld)
mtext("July SST", side=3, line=-1, adj=1)