select: Geometric subsetting

In raster: Geographic Data Analysis and Modeling

Geometric subsetting

Description

Geometrically subset Raster* or Spatial* objects by drawing on a plot (map).

Usage

## S4 method for signature 'Raster'
select(x, use='rec', ...)

## S4 method for signature 'Spatial'
select(x, use='rec', draw=TRUE, col='cyan', size=2, ...)

Arguments

x	Raster*, SpatialPoints*, SpatialLines*, or SpatialPolygons*
use	character: 'rec' or 'pol'. To use a rectangle or a polygon for selecting
draw	logical. Add the selected features to the plot?
col	color to use to draw the selected features (when draw=TRUE)
size	integer > 0. Size to draw the selected features with (when draw=TRUE))
...	additional arguments. None implemented

Value

Raster* or Spatial* object

See Also

click, crop

Examples

## Not run: 

# select a subset of a RasterLayer
r <- raster(nrow=10, ncol=10)
values(r) <- 1:ncell(r)
plot(r)
s <- select(r) # now click on the map twice

# plot the selection on a new canvas:
x11()
plot(s)


# select a subset of a SpatialPolygons object
p1 <- rbind(c(-180,-20), c(-140,55), c(10, 0), c(-140,-60), c(-180,-20))
hole <- rbind(c(-150,-20), c(-100,-10), c(-110,20), c(-150,-20))
p2 <- rbind(c(-10,0), c(140,60), c(160,0), c(140,-55), c(-10,0))
p3 <- rbind(c(-125,0), c(0,60), c(40,5), c(15,-45), c(-125,0))
pols <- SpatialPolygons( list(  Polygons(list(Polygon(p1), Polygon(hole)), 1),
      Polygons(list(Polygon(p2)), 2), Polygons(list(Polygon(p3)), 3)))
pols@polygons[[1]]@Polygons[[2]]@hole <- TRUE

plot(pols, col=rainbow(3))
ps <- select(pols) # now click on the map twice
ps

## End(Not run)

raster documentation built on Oct. 3, 2024, 1:08 a.m.