kmlLines
Create and write a KML file on the basis of a given Lines object
The function is used to create and write a KML file on the basis of a given Lines object (a list of Line objects) for the usage in Google Earth and Google Maps.
- Keywords
- spatial
Usage
kmlLines(obj=NULL, kmlfile=NULL,
name="R Lines", description="", col=NULL, visibility=1, lwd=1,
kmlname="", kmldescription="")
Arguments
- obj
a
Lines
orSpatialLinesDataFrame
object- kmlfile
if not
NULL
the name as character string of the kml file to be written- name
the name of the KML line
- description
the description of the KML line (HTML tags allowed)
- col
the stroke color (see also Color Specification) of the KML line
- visibility
if set to
1
orTRUE
specifies that the KML line should be visible after loading- lwd
the stroke width for the KML line
- kmlname
the name of the KML layer
- kmldescription
the description of the KML layer (HTML tags allowed)
Details
The function is used to convert a given Lines
object (a list of Line objects) or the first Lines
object listed in a passed SpatialLinesDataFrame
object into KML line(s). If kmlfile
is not NULL
the result will be written into that file. If kmlfile
is NULL
the generated KML lines will be returned (see also value). Function no longer uses append
greatly improving performance on large objects or lists.
For a passed Lines
object the function generates a <Style> tag whereby its id attribute is set to the passed object's ID.
Note that the geometries should be in geographical coordinates with datum WGS84.
The resulting KML line will be embedded in <Placemark><MultiGeometry><LineString>
.
Value
x is a list with the elements style
and content
containing the generated lines of the KML file as character vectors if kmlfile
is NULL
.
y is a list with the elements header
and footer
representing the KML file header and footer if obj
is NULL
.
Color Specification
The following color specifications are allowed: 'red'
, 2
, or as hex code '#RRGGBB'
resp. '#RRGGBBAA'
for passing the alpha value.
See Also
Examples
# NOT RUN {
# Maptools library required
library(maptools)
# load line object
rivers <- readShapeSpatial(system.file("shapes/fylk-val-ll.shp",
package="maptools")[1], proj4string=CRS("+proj=longlat +ellps=WGS84"))
# create kml file
td <- tempdir()
kmlfile <- paste(td, "rivers.kml", sep="/")
kmlLines(rivers, kmlfile = kmlfile, name = "R Lines",
description = "Hello!", col = "blue", visibility = 1, lwd = 1,
kmlname = "", kmldescription = "")
# }