rsaga.target {RSAGA} | R Documentation |
Define the resolution and extent of a target grid for interpolation by SAGA modules based on (1) fitting the extent to the input data, (2) an existing SAGA grid file, (3) user-defined parameters, or (4) the header data of an ASCII grid. Intended to be used with RSAGA's interpolation functions.
rsaga.target(target = c("user.defined", "grid.system", "target.grid", "header"), user.cellsize = 100, user.fit.extent = TRUE, user.x.extent, user.y.extent, user.bbox, system.nx, system.ny, system.xy, system.d, target.grid, header)
target |
character: method used for defining the target grid |
user.fit.extent |
Only for target="user.defined" :
logical; if TRUE , use the dimensions of an
input grid supplied to the SAGA module, e.g.
to rsaga.ordinary.kriging .
The other user.* variables should not be provided
if user.fit.extent=TRUE . |
user.cellsize |
Only for target="user.defined" :
raster resolution |
user.x.extent, user.y.extent |
Only for target="user.defined" :
numeric vectors of length 2: minimum and
maximum coordinates of grid cell center points |
user.bbox |
Only for target="user.defined" :
alternative way of specifying extent
(either use bbox OR user.*.extent ):
2x2 matrix of the form rbind(user.x.extent,user.y.extent) . |
system.nx, system.ny |
Only for target="grid.system" :
number of columns and rows of the grid |
system.xy |
Only for target="grid.system" :
numeric vector of length 2 giving the x and y coordinates
at the center of the grid's lower left cell |
system.d |
Only for target="grid.system" :
cellsize |
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 |
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 . |
This function is to be used with RSAGA functions
rsaga.ordinary.kriging
, rsaga.inverse.distance
,
rsaga.nearest.neighbour
and rsaga.modified.quadratic.shephard
.
Alexander Brenning
## Not run: # Krige attribute 0 from the points shapefile to # a grid with the same extent and resolutionn as the # (pre-existing) geology grid: rsaga.ordinary.kriging("points", "dem", field = 0, maxdist = 1000, target = rsaga.target(target="target.grid", target.grid = "geology")) # Specify a target grid manually (see above): rsaga.ordinary.kriging("points", "dem", field = 0, radius = 1000, target = rsaga.target("grid.system", system.nx = 200, system.ny = 300, system.xy = c(604853,7465013), system.d = 50)) ## End(Not run)