par(mfrow) or layout. To plot just a palette,
e.g. to get an x-y plot with points coloured according to a palette, use
drawPalette and then draw the main diagram.imagep(x, y, z, xlim, ylim, zlim, zclip = FALSE, flipy = FALSE, xlab = "",
ylab = "", zlab = "", zlabPosition = c("top", "side"),
decimate = TRUE, breaks, col, colormap, labels = NULL, at = NULL,
drawContours = FALSE, drawPalette = TRUE, drawTriangles = FALSE,
tformat, drawTimeRange = getOption("oceDrawTimeRange"),
filledContour = FALSE, missingColor = NULL, mgp = getOption("oceMgp"),
mar, mai.palette, xaxs = "i", yaxs = "i", cex = par("cex"), adorn,
axes = TRUE, main = "", axisPalette, debug = getOption("oceDebug"), ...)z are defined. In this case, both x and y
must be supplimage, which explains the same
descript"histogram" to have a flattened histogram (i.e. to maximally
increase contrast throughout the domain.)zlim. This only works if zlim is
provided. Clipped regions will be coloured with missingColor.
Thus, clipping an image is somewhat analogous tTRUE indicating that the image
should be flipped top to bottom (e.g. to produce a profile image
for a downward-looking acoustic-doppler profile).decimate=FALSE then every grid cell in the matrix will
be represented by a pixel in the image. Case 2 (the default).pretty, in determining clean break points.oce.colorsJet for a rainbow.colormap. If
provided, then colormap$breaks and colormap$col take
precedence over the present arguments breaks and col.
(All at).labels.drawPalette=TRUE, a palette is drawn at the right-hand side of the
main image. If drawPalette=FALSE, no palette is drawn, and the
right-hand side of the plot has a thin margdrawPalette.oce.plot.ts, for
plot types that call that function. (See strptime for the
format used.)x axis is a
time. If TRUE, then an indication of the time range of the
data (not the axis) is indicated at the top-left margin of the
graph. This is useful because the labels on time axes only indicateNULL to avoid making the indication.par(mgp), and
also for par(mar), computed from this. The default is
tighter than the R default, in order to use more space for the
data and less for the axes.par("mar"). If not
given, a reasonable value is calculated based on whether xlab and
ylab are empty strings.mai value used for the palette. Use with care."i") or not; see
par("xaxs").xaxs but for y axis.par("cex").expression to be performed immediately after
drawing the data panel.TRUE to get axes on the main image.axis(), passed to
drawPalette.xat and yat,
values that can be used by oce.grid to add a grid to the
plot.imagep is called. RStudio version 0.99.451 (released late in 2015) did
not have this problem, but it appeared in version 0.99.878 (released early
2016). The issue was reported to RStudio in January 2016. The workaround is
simple: open a new (and separate) plotting window with dev.new.filled.contour except that with imagep it is possible to
set the layout outside the function, which enables the creation
of plots with many image-palette panels. Note that the contour lines may not
coincide with the colour transitions, in the case of coarse images.Note that this does not use layout or any of the other screen
splitting methods. It simply manipulates margins, and draws two plots
together. This lets users employ their favourite layout schemes.
The palette is drawn before the image, so that further drawing can be done on
the image if desired, if the user prefers not to use the adorn argument.
NOTE: imagep is an analogue of image, and from that
it borrows a the convention that the number of rows in the matrix corresponds to
to x axis, not the y axis. (Actually, image permits
the length of x to match either nrow(z) or 1+nrow(z), but
here only the first is permitted.)
drawPalette, and is used by plot.adp,
plot.landsat, and other image-generating functions.library(oce)
# 1. simplest use
imagep(volcano)
# 2. something oceanographic (internal-wave speed)
h <- seq(0, 50, length.out=100)
drho <- seq(1, 3, length.out=200)
speed <- outer(h, drho, function(drho, h) sqrt(9.8 * drho * h / 1024))
imagep(h, drho, speed, xlab="Equivalent depth [m]",
ylab=expression(paste(Delta*rho, "[kg/m^3]")),
zlab="Internal-wave speed [m/s]")
# 3. fancy labelling on atan() function
x <- seq(0, 1, 0.01)
y <- seq(0, 1, 0.01)
angle <- outer(x,y,function(x,y) atan2(y,x))
imagep(x, y, angle, filledContour=TRUE, breaks=c(0, pi/4, pi/2),
col=c("lightgray", "darkgray"),
at=c(0, pi/4, pi/2),
labels=c(0, expression(pi/4), expression(pi/2)))
# 4. a colormap case
data(topoWorld)
cm <- colormap(name="gmt_globe")
imagep(topoWorld, colormap=cm)Run the code above in your browser using DataLab