image.seas.sum {seas} | R Documentation |
Graphically display a seasonal sum object, as well as the method of solution of the median/quantile “normal”
## S3 method for class 'seas.sum': image(x, var, norm = "days", start=1, rep=0, zlim, alim, palette = colorRampPalette(c("white","blue"))(64), year.filter, power, contour=TRUE, show.median, main, ...)
x |
a seas.sum object |
var |
the desired variable to show, otherwise will use the prime
variable, defined in x |
norm |
variable to normalize by, usually "days" , to
produce unit/day |
start |
starting bin number; e.g., for monthly sums, if
start=5 , the plot will start on "May" at the left-hand side;
show.median cannot be produced if start is greater
than one, since the annual sums (row-wise) would be a mix of
different annums |
rep |
repetition of the bins (columns) |
zlim |
range of normalized values displayed; this can be either a
single number for the maximum (minimum set to zero), or a
c(min,max) range with a defined minimum |
alim |
if show.median , this is the range for the annual
sums; this can either be a singe number for the maximum (minimum set
to zero, or a c(min,max) range with a defined minimum |
palette |
colours for image ; the use of
colorRampPalette is recommended |
year.filter |
specifies the annual seasons to display |
power |
this transforms the normalized values for the colours to
a power (^ ), such as 0.5 for square-root
(sqrt ), or others; this can help improve the contrast
in the display of data, but the quantities displayed in the
colour-bar and contours remain untransformed |
contour |
logical ; show contours in lower left-hand plot |
show.median |
logical ; show how the median calculation is
achieved graphically (computationally it is done using a secant
method); see seas.norm for more information on this
method; this can only be shown if the annums (rows) are complete, so
start must be 1, and rep must be 0 (otherwise the
row-wise sums would not be the annual sums) |
main |
main title for plot, otherwise it will automatically be
generated; NA suppresses a title, and automatically adjusts
the device margins |
... |
ignored |
This is a graphical representation of a seas.sum
object,
and is far more informative than a traditional precipitation
“normal” (i.e., precip.norm
or
precip.norm
)
If norm = "days"
and show.median = TRUE
(default), the
seasonal sums appear in right-hand frames. Horizontal and vertical
lines indicate a ‘normal’ from the image, whereby the sum of
the quantile is equal to the median of the annual amount. This
numerical solution is found using seas.norm
.
M.W. Toews
See SeasOpts
to modify other aspects of the plot
data(mscdata) dat <- mksub(mscdata, id=1108447) dat.ss <- seas.sum(dat, width="mon") image(dat.ss) image(dat.ss,contour=FALSE) image(dat.ss,norm="active",start=6,rep=5) # different start day (not Jan 1st) dat2.ss <- seas.sum(dat,start.day=as.Date("2001-08-01")) image(dat2.ss) image(dat2.ss,power=2) image(dat2.ss,palette=rainbow(64),main=NA) # no title image(dat2.ss,palette=colorRampPalette(c("white","darkgreen"))(16)) image(dat2.ss,"snow") image(dat2.ss,"snow",power=0.5) # growing degree days for 10 degC dat$gdd10 <- dat$t_mean - 10 dat$gdd10[dat$gdd10<0] <- 0 attr(dat$gdd10,"long.name") <- "growing degree days" dat3.ss <- seas.sum(dat,var="gdd10") image(dat3.ss,"gdd10",palette=colorRampPalette(c("white","red"))(64))