plot.section {oce} | R Documentation |
Plot a CTD section.
## S3 method for class 'section': plot(x, field=NULL, at=NULL, labels=TRUE, grid=FALSE, contour.levels=NULL, contour.labels=NULL, station.indices, coastline=NULL, map.xlim=NULL, xtype="distance", ytype="depth", legend.loc="bottomright", ...)
x |
a section object, e.g. as created by
make.section . |
field |
is the field to plot. Common options are
"temperature" , "salinity" , and "density" ,
although plot.section will accept any named field that is
present in the constituent CTD profiles. If NULL (the default)
is given, then temperature, salinity and density are graphed. If a
field is specified, then it is also possible to specify the
contour.levels and contour.labels (see below). |
at |
if NULL (the default), the x axis will indicate the
distance of the stations from the first in the section. (This may
give errors in the contouring routine, if the stations are not present
in a geographical order.) If a list, then it indicates the values at
which stations will be plotted. |
labels |
either a logical, indicating whether to put labels on
the x axis, or a vector that is a list of labels to be placed at the x
positions indicated by at . |
grid |
if TRUE , points are drawn at data locations. |
contour.levels |
if not NULL , and if a field was
specified, this specifies contour levels (see details) |
contour.labels |
if not NULL , and if a field was
specified, this specifies contour labels (see details) |
station.indices |
optional list of the indices of stations to
use. Note that these are indices, not the names of stations, e.g. to
focus on the first four stations, use station.numbers=c(1,4) . |
coastline |
optional coastline to be used in a station
map |
map.xlim |
optional xlim for station location, which can be helpful in ensuring that a recognizable coastline can be seen |
xtype |
type of x axis, for contour plots, either
"distance" for distance (in km) to the first point in the
section, or "track" for distance along the cruise track.
Note that if the x values are not in order, they will be put in
order (which may make no sense) and a warning will be printed. |
ytype |
type of y axis for contour plots, either
"pressure" for pressure (in dbar, with zero at the surface)
or "depth" for depth (in m below the surface, calculated
from pressure with sw.depth ). |
legend.loc |
location of legend, as supplied to legend . |
... |
optional arguments passed to the contouring function,
e.g. using labcex=1 will increase the size of contour labels. |
Creates a summary plot for a CTD section. If a field
is
supplied, then just that single field is contoured. If no field
is supplied, then temperature, salinity, and sigma are contoured. A
location plot is also drawn if a coastline
is provided; in
this, the first station in the section is indicated with a different
symbol than the rest.
The y-axis for the contours is pressure, plotted in the conventional
reversed form, so that the water surface appears at the top of the
plot. The x-axis is more complicated. If at
is not supplied,
then the routine calculates x as the distance between the first
station in the section and each of the other stations. (This will
produce an error if the stations are not ordered geographically,
because the contour
routine cannot handle non-increasing
axis coordinates.) If at
is specified, then it is taken to be
the location, in arbitrary units, along the x-axis of labels specified
by labels
; the way this works is designed to be the same as for
axis
.
None.
Dan Kelley
Sections may be created with make.section
or
read.section
, and may be summarized with
summary.section
.
library(oce) # Halifax Harbour data(section) data(coastline.hal) plot(section, coastline=coastline.hal) # Gulf Stream data(a03) Gulf.Stream <- subset(a03, indices=124:102) Gulf.Stream.gridded <- section.grid(Gulf.Stream, p=seq(0,2000,100)) data(coastline.world) plot(Gulf.Stream.gridded, coastline=coastline.world, map.xlim=c(-80,-60))