RSAGA (version 1.4.0)

rsaga.target: Define target grid for interpolation

Description

Define the resolution and extent of a target grid for interpolation by SAGA modules based on (1) user-provided x/y coordinates, (2) an existing SAGA grid file, or (3) the header data of an ASCII grid. Intended to be used with RSAGA's interpolation functions.

Usage

rsaga.target(
  target = c("user.defined", "target.grid", "header"),
  user.cellsize = 100,
  user.x.extent,
  user.y.extent,
  target.grid,
  header,
  env = rsaga.env()
)

Arguments

target

character: method used for defining the target grid

user.cellsize

Only for target="user.defined": raster resolution (in the grid's map units)

user.x.extent

See user.y.extent

user.y.extent

Only for target="user.defined": numeric vectors of length 2: minimum and maximum coordinates of grid cell center points

target.grid

Only for target="target.grid": character string giving the name of a SAGA grid file that specifies the extent and resolution of the target grid; this target grid file may be overwritten, depending on the specifics of the SAGA GIS module used.

header

Only for target="header": list: ASCII grid header (as returned e.g. by read.ascii.grid.header()) or defined manually; must at least have components ncols, nrows, cellsize, and either x/yllcorner or x/yllcenter.

env

A SAGA geoprocessing environment, see rsaga.env().)

See Also

read.ascii.grid.header()

Examples

if (FALSE) {
# IDW interpolation of attribute "z" from the point shapefile
# 'points.shp' to a grid with the same extent and resolution
# as the (pre-existing) geology grid:
rsaga.inverse.distance("points", "dem", field = "z", maxdist = 1000,
    target = rsaga.target(target="target.grid",
    target.grid = "geology"))
}