Add Grid Values to Points
Hi Tim,
the most recent release of RSAGA has a wrapper function for this module
that is called rsaga.add.grid.values.to.points; try this:
rsaga.add.grid.values.to.points("test", c("slope", "aspect"),
"add_grid", method = "nearest.neighbour", env = myenv)
(Note that the wrapper function uses default file extensions.)
The problem with your call is that multiple file names have to be passed
to SAGA_CMD in the form
GRIDS=file1.sgrd;file2.sgrd;file3.sgrd
If you don't collapse the vector with semicolons, the geoprocessor will say
GRIDS=file1.sgrd file2.sgrd file3.sgrd
and SAGA_CMD will assume that file2.sgrd is the next argument.
OK, maybe something to be changed in the next version of the
geoprocessor, which is just a low-level workhorse.
rsaga.geoprocessor("shapes_grid", 0,
param = list(SHAPES = "test.shp",
GRIDS = paste(c("slope.sgrd", "aspect.sgrd"), collapse=";"),
RESULT = "add_grid.shp", INTERPOL = 0),
env = myenv)
I hope this helps...
Alex
Tim H?ring wrote:
Hello to everybody,
I?m trying to use the SAGA tool "Add Grid Values to Points" in R using the RSAGA package
("shapes_grid", 0) but there is an error message I can`t figure out.:
rsaga.geoprocessor("shapes_grid",0, list(SHAPES="test.shp", GRIDS=list("slope.sgrd",
"aspect.sgrd"), RESULT="add_grid.shp", INTERPOL=0), env=myenv)
SAGA CMD 2.0.3
library path: C:/Programme/saga_vc/modules
library name: shapes_grid
module name : Add Grid Values to Points
author : (c) 2003 by O.Conrad
error: executing module [Add Grid Values to Points]
Usage: -silent -SHAPES <str> -GRIDS <str> -RESULT <str> [-INTERPOL <num>]
-SHAPES:<str> Points
Shapes (input)
-GRIDS:<str> Grids
Grid list (input)
-RESULT:<str> Result
Shapes (output)
-INTERPOL:<num> Interpolation
Choice
Available Choices:
[0] Nearest Neighbor
[1] Bilinear Interpolation
[2] Inverse Distance Interpolation
[3] Bicubic Spline Interpolation
[4] B-Spline Interpolation
'add_grid.shp' is not a correct numeric value for option 'INTERPOL'.
I can`t explain why R is trying to understand the expression "add_grid.shp" as the
Interpolationmethod even though it is previous to the INTERPOL expression in the
command.
Any ideas?
Thank`s a lot.
TIM
Alexander Brenning brenning at uwaterloo.ca - T +1-519-888-4567 ext 35783 Department of Geography and Environmental Management University of Waterloo 200 University Ave. W - Waterloo, ON - Canada N2L 3G1 http://www.fes.uwaterloo.ca/geography/faculty/brenning/