| lpp {spatstat} | R Documentation |
Creates an object of class "lpp" that represents
a point pattern on a linear network.
lpp(X, L)
X |
Locations of the points. A matrix or data frame of coordinates,
or a point pattern object (of class
|
L |
Linear network (object of class |
This command creates an object of class "lpp" that represents
a point pattern on a linear network.
Normally X is a point pattern. The points of X should lie
on the lines of L.
Alternatively X may be a matrix or data frame containing at
least two columns.
Usually
the first two columns of X will be interpreted
as spatial coordinates, and any remaining columns as marks.
The exception occurs if X is a data frame with columns named
x, y, seg and tp. Then
x and y will be interpreted as spatial
coordinates, and seg and tp as local
coordinates, with seg indicating which line segment of
L the point lies on, and tp indicating how far along
the segment the point lies (normalised to 1). Any remaining columns
will be interpreted as marks.
An object of class "lpp".
Also inherits the class "ppx".
The internal format of "lpp" objects was changed in
spatstat version 1.28-0.
Objects in the old format are still handled correctly,
but computations are faster in the new format.
To convert an object X from the old format to the new format,
use X <- lpp(as.ppp(X), as.linnet(X)).
Ang Qi Wei aqw07398@hotmail.com and Adrian Baddeley Adrian.Baddeley@uwa.edu.au http://www.maths.uwa.edu.au/~adrian/
as.lpp for converting data to an lpp object.
See methods.lpp and
methods.ppx for other methods applicable
to lpp objects.
Calculations on an lpp object:
intensity.lpp,
distfun.lpp,
nndist.lpp,
nnwhich.lpp,
nncross.lpp,
nnfun.lpp.
Summary functions:
linearK,
linearKinhom,
linearpcf,
linearKdot,
linearKcross,
linearmarkconnect, etc.
Random point patterns on a linear network can be generated by
rpoislpp or runiflpp.
See linnet for linear networks.
example(linnet) xx <- list(x=c(-1.5,0,0.5,1.5), y=c(1.5,3,4.5,1.5)) X <- lpp(xx, letterA) plot(X) X summary(X)