Plot contours on an existing map.
mapContour(longitude, latitude, z, nlevels = 10,
levels = pretty(range(z, na.rm = TRUE), nlevels), labcex = 0.6,
drawlabels = TRUE, underlay = "erase", col = par("fg"),
lty = par("lty"), lwd = par("lwd"), debug = getOption("oceDebug"))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.
vector of latitudes of points to be plotted.
matrix to be contoured. The number of rows and columns in z
must equal the lengths of longitude and latitude, respectively.
number of contour levels, if and only if levels is not supplied.
vector of contour levels.
logical value or vector indicating whether to draw contour
labels. If the length of drawlabels is less than the number of
levels specified, then rep is used to increase the length,
providing a value for each contour line. For those levels that are thus
indicated, labels are added, at a spot where the contour line is
closest to horizontal on the page. First, though, the region underneath
the label is filled with the colour given by par("bg").
See “Limitations” for notes on the status of contour
labelling, and its limitations.
character value relating to handling labels. If
this equals "erase" (which is the default), then the contour line
is drawn first, then the area under the label is erased (filled with
white 'ink'), and then the label is drawn. This can be useful
in drawing coarsely-spaced labelled contours on top of finely-spaced
unlabelled contours. On the othr hand, if underlay equals
"interrupt", then the contour line is interrupted in the
region of the label, which is closer to the scheme used by the
base contour function.
type of the contour line, as for par("lty"),
except for lengthening, as described for col.
width of the contour line, as for par("lwd"),
except for lengthening, as described for col and lty.
an integer specifying whether debugging information is
to be printed during the processing. This is a general parameter that
is used by many oce functions. Generally, setting debug=0
turns off the printing, while higher values suggest that more information
be printed. If one function calls another, it usually reduces the value of
debug first, so that a user can often obtain deeper debugging
by specifying higher debug values.
Adds contour lines to an existing map, using mapLines.
The ability to label the contours was added in February, 2019, and
how this works may change through the summer months of that year.
Note that label placement in mapContour is handled differently
than in contour.
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,
usrLonLat, utm2lonlat
# NOT RUN {
library(oce)
data(coastlineWorld)
if (require(ocedata)) {
data(levitus, package="ocedata")
par(mar=rep(1, 4))
mapPlot(coastlineWorld, projection="+proj=robin", col="lightgray")
mapContour(levitus[['longitude']], levitus[['latitude']], levitus[['SST']])
}
# }
# NOT RUN {
# }
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