Interaction: Interaction with trellis objects.

Description

chooseRegion provides a set of points (in the form of a SpatialPoints) inside a region defined by several mouse clicks. identifyRaster labels and returns points of a trellis graphic according to mouse clicks.

Usage

chooseRegion(sp = TRUE, proj = CRS("+proj=latlon +ellps=WGS84"))
## S3 method for class 'Raster':
identifyRaster(object, layer=1, values=FALSE, pch=13, cex=0.6, col='black',...)

Arguments

docType

methods

Details

When called, these functions wait for the user to identify points (in the panel being drawn) via mouse clicks. Clicks other than left-clicks close the region (for chooseRegion) and the procedure (for identifyRaster).

Examples

Run this code

f <- system.file("external/test.grd", package="raster")
r <- raster(f)
levelplot(r)
##Do not close the last graphical window
##Use the left button of the mouse to identify points and the right button to finish
chosen_r <- identifyRaster(r, values=TRUE)
chosen_r
s <- stack(r, r-500, r+500)
levelplot(s)
chosen_s <- identifyRaster(s, values=TRUE)
chosen_s

##The package mgcv is needed for the next example
##Use the left button of the mouse to build a border with points, and the right button to finish.
##The points enclosed by the border will be highlighted and returned as a SpatialPoints object.
levelplot(s)
reg <- chooseRegion()
summary(reg)

##Solar irradiation data from CMSAF
##Data available from http://www.box.net/shared/rl51y1t9sldxk54ogd44

old <- getwd()
##change to your folder...
setwd('CMSAF')
listFich <- dir(pattern='2008')
stackSIS <- stack(listFich)
stackSIS <- stackSIS*24 ##from irradiance (W/m2) to irradiation Wh/m2
setwd(old)

idx <- seq(as.Date('2008-01-15'), as.Date('2008-12-15'), 'month')

SISmm <- setZ(stackSIS, idx)
names(SISmm) <- month.abb

levelplot(SISmm)

##Do not close the last graphical window
##Interaction
##Use the left button of the mouse to identify points and the right button to finish
chosen <- identifyRaster(SISmm, layer=3, values=TRUE)
chosen
##Use the left button of the mouse to build a border with points, and the right button to finish.
##The points enclosed by the border will be highlighted and returned as a SpatialPoints object.
reg <- chooseRegion()
summary(reg)