plot.ppp {spatstat} | R Documentation |
Plot a two-dimensional spatial point pattern
plot.ppp(x, main, ..., chars, cols, use.marks=TRUE, add=FALSE, maxsize)
x |
The spatial point pattern to be plotted.
An object of class "ppp" ,
or data which can be converted into
this format by as.ppp() .
|
main |
text to be displayed as a title above the plot. |
... |
extra arguments that will be passed to the plotting functions
plot.default (see par for possible
options) or symbols .
|
chars |
the plotting characters which should be used to represent the points of different types, in the case of a multitype point pattern. |
cols |
the colours which should be used to plot the points of different types, in the case of a multitype point pattern. |
use.marks |
logical flag; if TRUE , plot points using a different
plotting symbol for each mark;
if FALSE , only the locations of the points will be plotted,
using points() .
|
add |
logical flag; if TRUE ,
just the points are plotted, over the existing plot.
A new plot is not created, and
the window is not plotted.
|
maxsize |
the maximum radius of the circles plotted.
If x is a marked point pattern with
numerical marks, the marks are plotted as circles with
maximum radius maxsize
(in the same units as the coordinates of
the point pattern). There is a sensible default.
|
This is the plot
method for
point pattern datasets (of class "ppp"
, see ppp.object
).
First the observation window x$window
is plotted
using plot.owin
.
Then the locations of the points are plotted.
If the points do not have marks (i.e. x$marks
is absent)
or if use.marks = FALSE
,
then the locations of the points will be plotted
using a single plot character. This character can be changed
by the extra argument pch
; see the examples.
For a marked point pattern (where x$marks
is not null)
each point will be represented by a graphical symbol plotted at the
location of the point.
The graphical representation of the marks depends
on their storage mode:
x$marks
is a factor, then
each level of the factor is
represented by a different plot character.
x$marks
is a numeric vector,
the marks are rescaled to the unit interval and
each point is represented by a circle
with radius proportional to the rescaled mark
(if the value is positive) or a square with side proportional
to the absolute value of the rescaled mark (if the value is negative).
points(..., pch=i)
.
If the arguments chars
and/or cols
are supplied,
they should be vectors of the same length
as sort(unique(x$marks))
, and then the ith smallest mark
will be plotted using character chars[i]
and colour
cols[i]
.
The argument cols
is incompatible with
the generic plot argument col
. If both are given,
an error is generated and no plot is produced.
NULL
, or a vector giving the correspondence between
mark values and plotting characters.
Adrian Baddeley adrian@maths.uwa.edu.au http://www.maths.uwa.edu.au/~adrian/ and Rolf Turner rolf@math.unb.ca http://www.math.unb.ca/~rolf
ppp.object
,
plot
,
par
,
points
,
plot.owin
,
symbols
library(spatstat) data(cells) plot(cells) # multitype data(lansing) plot(lansing) # marked by a real number data(longleaf) plot(longleaf) # just plot the points plot(longleaf, use.marks=FALSE) plot(unmark(longleaf)) # equivalent # controlling COLOURS plot(cells, col="blue") plot(lansing, cols=c("black", "yellow", "green", "pink", "blue","red","white") plot(longleaf, fg="blue") # use selected plot characters lma <- sort(unique(longleaf$marks)) adult <- ifelse(lma >= 30, "o", "+") plot(longleaf, chars = adult) # make the plotting symbols larger (for publication at reduced scale) plot(cells, cex=2)