spatstat (version 1.42-2)

as.lpp: Convert Data to a Point Pattern on a Linear Network

Description

Convert various kinds of data to a point pattern on a linear network.

Usage

as.lpp(x, y=NULL, seg=NULL, tp=NULL, ...,
         marks=NULL, L=NULL, check=FALSE, sparse)

Arguments

x,y

Vectors of cartesian coordinates, or any data acceptable to xy.coords. Alternatively x can be a point pattern on a linear network (object of class "lpp")

seg,tp

Optional local coordinates. Vectors of the same length as x,y. See Details.

...

Ignored.

marks

Optional marks for the point pattern. A vector or factor with one entry for each point, or a data frame or hyperframe with one row for each point.

L

Linear network (object of class "linnet") on which the points lie.

check

Logical. Whether to check the validity of the spatial coordinates.

sparse

Optional logical value indicating whether to store the linear network data in a sparse matrix representation or not. See linnet.

Value

• A point pattern on a linear network (object of class "lpp").

Details

This function converts data in various formats into a point pattern on a linear network (object of class "lpp"). The possible formats are:

• xis already a point pattern on a linear network (object of class"lpp"). Thenxis returned unchanged.
• xis a planar point pattern (object of class"ppp"). Thenxis converted to a point pattern on the linear networkLusinglpp.
• x,y,seg,tpare vectors of equal length. These specify that theith point has Cartesian coordinates(x[i],y[i]), and lies on segment numberseg[i]of the networkL, at a fractional positiontp[i]along that segment (withtp=0representing one endpoint andtp=1the other endpoint of the segment).
• seg,tpareNULL, andx,yare data in a format acceptable toxy.coordsspecifying the Cartesian coordinates.

See Also

lpp.

Examples

A <- as.psp(simplenet)
   X <- runifpointOnLines(10, A)
   is.ppp(X)
   Y <- as.lpp(X, L=simplenet)