R: Line midpoints

SpatialLinesMidPoints {maptools} | R Documentation

## Line midpoints

### Description

The function onverts SpatialLinesDataFrame to SpatialPointsDataFrame with points at the midpoints of the line segments.

### Usage

    SpatialLinesMidPoints(sldf)

### Arguments

`sldf` | A SpatialLines or SpatialLinesDataFrame object

### Details

The function builds a SpatialPointsDataFrame from the midpoints of Line objects belonging to Lines objects in an object inheriting from a Spatial Lines object. The output data slot contains an index variable showing which Lines object the midpoints belong to.

### Value

A SpatialPointsDataFrame object created from the input object.

### Author(s)

Jonathan Callahan, modified by Roger Bivand

### Examples

    xx <- readShapeLines(system.file("shapes/fylk-val.shp", package="maptools")[1],
     proj4string=CRS("+proj=utm +zone=33 +datum=WGS84"))
    plot(xx, col="blue")
    spdf <- SpatialLinesMidPoints(xx)
    plot(spdf, col="orange", add=TRUE)

[Package maptools version 0.9-9 Index]