plotKML (version 0.5-4)

kml_layer.Raster: Writes raster objects to KML

Description

Writes rasters to PNG images and makes a KML code (ground overlays). Works with "RasterLayer" and "RasterStack" class objects. Target attributes can be specified using aesthetics arguments (e.g. "colour").

Usage

kml_layer.Raster(obj, subfolder.name = paste(class(obj)), plot.legend = TRUE, 
     metadata = NULL, raster_name, 
     png.width = ncol(obj), png.height = nrow(obj), 
     min.png.width = 800, TimeSpan.begin, TimeSpan.end,
     layer.name, png.type = "cairo-png", ...)

Arguments

obj

object of class "RasterLayer", "SpatialPixelsDataFrame" or "SpatialGridDataFrame"

subfolder.name

character; optional subfolder name

plot.legend

logical; specify whether a map legend should be generated automatically

metadata

(optional) specify the metadata object

raster_name

(optional) specify the output file name (PNG)

png.width

(optional) width of the PNG file

png.height

(optional) height of the PNG file

min.png.width

(optional) minimum width of the PNG file

TimeSpan.begin

object of class "POSIXct"; (optional) begin of the sampling period

TimeSpan.end

object of class "POSIXct"; (optional) end of the sampling period

layer.name

character; optional layer name

png.type

character; PNG type

...

additional aesthetics arguments

Details

Google Earth does not properly handle a 24-bit PNG file which has a single transparent color (read more at http://groups.google.com/group/earth-help/{Google Earth Help}). To force transparency, plotKML will try to set it using the -matte -transparent "#FFFFFF" option in the http://www.imagemagick.org/Usage/masking/{ImageMagick convert program} (ImageMagick needs to be installed separately and located using plotKML.env()). On some Unix run machines the png.type argument has to be set manually to avoid producing empty PNGs.

See Also

kml-methods, kml_open, kml_layer.RasterBrick, plotKML-method

Examples

data(eberg_grid)
library(sp)
coordinates(eberg_grid) <- ~x+y
gridded(eberg_grid) <- TRUE
proj4string(eberg_grid) <- CRS("+init=epsg:31467")
data(SAGA_pal)
library(raster)
r <- raster(eberg_grid["TWISRT6"])
# KML plot with a single raster:
kml(r, colour_scale = SAGA_pal[[1]], colour = TWISRT6)