R: Interaction with trellis objects.

Interaction {rasterVis} | R Documentation

## 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 = as.character(NA))
    ## S4 method for signature 'Raster'
    identifyRaster(object, layer=1, values=FALSE, pch=13, cex=0.6, col='black',...)

### Arguments

`sp` | logical, if TRUE the result is a `SpatialPoints` object, otherwise it is a logical vector as returned by `in.out`
`proj` | A character string for the `proj4string` of `SpatialPoints`.
`object` | A Raster object.
`layer` | A numeric or character which should indicate the layer to be chosen.
`values` | logical, if TRUE the values are returned.
`pch, cex, col` | Graphical parameters for `panel.identify` and `panel.link.splom`.
`...` | Additional arguments for `trellis.focus`,`panel.link.splom` and `panel.identify`.

### 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`).

### Note

`chooseRegion` needs the package `mgcv` to be installed.

### Author(s)

Oscar Perpiñán Lamigueiro

### See Also

`panel.identify`,`panel.link.splom`, `trellis.focus`, `grid.locator`

### Examples

    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

    ## Not run:
    ##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)

    ## End(Not run)

    ## Not run:
    ##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)

    ## End(Not run)

[Package rasterVis version 0.44 Index]