plotKML (version 0.2-4)

kml_layer.RasterBrick: Export a time series of images to KML

Description

Writes a series of images to PNGs and uses them to create ground overlays. Works only with "RasterBrick" class objects with time dimension specified via the "@zvalue".

Usage

kml_layer.RasterBrick(obj, plot.legend = TRUE, dtime = "", tz = "GMT", 
          z.lim = c(min(obj@data@min, na.rm = TRUE),
          max(obj@data@max, na.rm = TRUE)), 
          colour_scale = get("colour_scale_numeric", envir = plotKML.opts),
          home_url = get("home_url", envir = plotKML.opts),
          metadata = NULL, html.table = NULL, ...)

Arguments

obj

object of class "RasterBrick" (a time series of images)

plot.legend

logical; specify whether a map legend should be generated automatically

dtime

temporal support (point or block) expressed in seconds

tz

referent time zone

z.lim

upper and lower limits (unique for all maps in the time series); the function by default uses the absolute minimum and maximum in values

colour_scale

color palette; by default uses the color scale for numeric variables

home_url

(optional) URL directory / location of the images

metadata

(optional) the metadata object

html.table

(optional) the description block (html)

...

additional arguments (see aesthetics)

Details

This method is recommended for visualization of numeric bands representing the same variable i.e. time series of images. To export a stack of images of different type see kml_layer.Raster. If the "@zvalue" slot is empty, dates will be added by subtracting days from the current day with 1--day increments.

See Also

kml-methods, kml_open, kml_layer.Raster

Examples

data(LST)
coordinates(LST) <- ~x+y
gridded(LST) <- TRUE
proj4string(LST) <- CRS("+proj=utm +zone=33 +datum=WGS84 +units=m")
# get the dates from the file names:
dates <- sapply(strsplit(names(LST), "LST"), function(x){x[[2]]})
LST <- brick(LST)
LST@title = "Time series of MODIS Land Surface Temperature images"
LST <- setZ(LST, format(as.Date(dates, "%Y_%m_%d"), "%Y-%m-%dT%H:%M:%SZ"))
data(SAGA_pal)
# time dimension defined via zvalue slot:
getZ(LST)[c(1,12,24)]
# subset to 3 images:
LSTs <- brick(raster(LST, 1), raster(LST, 12), raster(LST, 24))
LST_ll <- reproject(LSTs, program="FWTools")
# copy the dates:
LST_ll <- setZ(LST_ll, getZ(LST)[c(1,12,24)])
# KML plot with block temporal support of 8 days:
kml(LST_ll, colour_scale=SAGA_pal[[1]], dtime=8*24*60^2)