select: Spatial selection

In rspatial/terra: Spatial Data Analysis

Spatial selection

Description

Geometrically subset SpatRaster or SpatVector (to be done) by drawing on a plot (map).

Note that for many installations this does to work well on the default RStudio plotting device. To work around that, you can first run dev.new(noRStudioGD = TRUE) which will create a separate window for plotting, then use plot() followed by sel() and click on the map. It may also help to set your RStudio "Tools/Global Options/Appearance/Zoom" to 100

Usage

## S4 method for signature 'SpatRaster'
sel(x, ...)

## S4 method for signature 'SpatVector'
sel(x, use="rec", show=TRUE, col="cyan", draw=TRUE, ...)

Arguments

x	SpatRaster or SpatVector
use	character indicating what to draw. One of "rec" (rectangle) or "pol" (polygon)
show	logical. If TRUE the selected geometries are shown on the map
col	color to be used for drawing if draw=TRUE
draw	logical. If TRUE the area drawn to select geometries is shown on the map
...	additional graphics arguments for drawing the selected geometries

Value

SpatRaster or SpatVector

See Also

crop and intersect to make an intersection and click and text to see cell values or geometry attributes.

Use draw to draw a SpatExtent of SpatVector that you want to keep.

Examples

## Not run: 
# select a subset of a SpatRaster
r <- rast(nrows=10, ncols=10)
values(r) <- 1:ncell(r)
plot(r)
s <- sel(r) # now click on the map twice

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

# vector
f <- system.file("ex/lux.shp", package="terra")
v <- vect(f)
plot(v)
x <- sel(v) # now click on the map twice
x

## End(Not run)

rspatial/terra documentation built on Jan. 7, 2025, 6:27 p.m.