plot.section {oce} | R Documentation |
Plot a CTD section.
## S3 method for class 'section': plot(x, field=NULL, at=NULL, labels=TRUE, grid=FALSE, station.indices, coastline=NULL, map.xlim=NULL, ...)
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. |
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. |
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 |
... |
optional arguments passed to the contouring function, e.g. using
labcex=1 will increase the size of contour labels. Probably the most
common use, though, is to specify contours for individually plotted fields, e.g. plot.section(section, field="temperature", levels=seq(0,30,1)) gives
temperature contours from 0 to 30C in intervals of 1C. |
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 <- section.subset(a03, 124:102) Gulf.Stream.gridded <- section.grid(Gulf.Stream, p=seq(0,2000,10)) data(coastline.world) plot(Gulf.Stream.gridded, coastline=coastline.world, map.xlim=c(-80,-60))