lpp  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 
... 
Ignored. 
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.
An 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.
Another exception occurs if X
is a data frame with columns named
seg
and tp
. Then
seg
and tp
will be interpreted as local
coordinates, as above, and the spatial coordinates
x,y
will be computed from them.
Any remaining columns will be interpreted as marks.
If X
is missing or NULL
, the result is an empty
point pattern (i.e. containing no points).
An object of class "lpp"
.
Also inherits the class "ppx"
.
The internal format of "lpp"
objects was changed in
spatstat version 1.280
.
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))
.
and \adrian
Installed datasets which are "lpp"
objects:
chicago
,
dendrite
,
spiders
.
See 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.
# letter 'A' v < ppp(x=(2):2, y=3*c(0,1,2,1,0), c(3,3), c(1,7)) edg < cbind(1:4, 2:5) edg < rbind(edg, c(2,4)) letterA < linnet(v, edges=edg) # points on letter A 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) # empty pattern lpp(L=letterA)
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