select function

Geometric subsetting

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

## 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

See Also

click, crop

Returns

Raster* or Spatial* object

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)