nowrapSpatialLines {sp} | R Documentation

## Split SpatialLines components at offset

### Description

When recentering a world map, most often from the "Atlantic" view with longitudes with range -180 to 180, to the "pacific" view with longitudes with range 0 to 360, lines crossing the offset (0 for this conversion) get stretched horizonally. This function breaks Line objects at the offset (usually Greenwich), inserting a very small gap, and reassembling the Line objects created as Lines. A similar function for rings is found in the spgpc package.

### Usage

    nowrapSpatialLines(obj, offset = 0, eps = rep(.Machine$double.eps, 2))

### Arguments

`obj` | A Spatial Lines object
`offset` | default 0, untried for other values
`eps` | vector of two fuzz values, both default double.eps

### Value

A Spatial Lines object

### Author(s)

Roger Bivand

### Examples

    Sl <- SpatialLines(list(Lines(list(Line(cbind(sin(seq(-4,4,0.4)), seq(1,21,1)))))), proj4string=CRS("+proj=latlong"))
    summary(Sl)
    #lapply(sapply(getSLlinesSlot(Sl), getLinesLinesSlot), bbox)
    #lapply(sapply(getSLlinesSlot(recenter(Sl)), getLinesLinesSlot), bbox)
    nwSL <- nowrapSpatialLines(Sl)
    summary(nwSL)
    #lapply(sapply(getSLlinesSlot(nwSL), getLinesLinesSlot), bbox)
    #lapply(sapply(getSLlinesSlot(recenter(nwSL)), getLinesLinesSlot), bbox)

[Package sp version 0.7-12 Index]