On 04/04/2011 11:53 AM, Claus Haslauer wrote:
> we are trying to do a conditional simulation. Below is our gstat command file. The comments should explain what we're trying to do. It seems to read the measurements fine, but it produces no output.
> The issue is: how do we tell gstat the locations where it should simulate?
> In the manual, in example 7, there is a mask command. It references 'mask_map'. We're not sure what this file should contain.
> Also, what is the command "predictions" for?
the mask is a raster image, e.g. in asciigrid command (or any
gdal-readable, if gstat was compiled with gdal support).
if your locations are irregular points, use the
data(): 'file', x=1, y=2;
> Ideally, we would like to specify the locations where we want to simulate in a manner similar to this:
> simloc(alpha): 'xzy.dat', x=1, y=2, z=3;
> Is that possible?
yes, substitute simloc(alpha) with data().
> Also, what is zmap for?
the height of a map, in case the coordinates of your data are
> Thanks for your help,
No problem. Please note that development of gstat stand alone has halted
8 years ago, all development takes place in the gstat R package.
> ## Gaussian simulation, conditional upon data
> # file contains measurements locations and values (x,y,z,F1)
> data(alpha): 'top_xyzK.txt', x=1, y=2, z=3, v=4, sk_mean=0.0, max=20;
> # spatial gaussian model
> variogram(alpha): 0.25 Nug(0.0) + 0.75 Sph(9.4);
> # gaussian simulation = gs
> method: gs;
> # locations (x,y,z) where we want to simulate
> # not sure which is correct
> # mask: 'grid_Top_3d_05m_Simloc.txt';
> predictions(alpha): 'grid_Top_3d_05m_Simloc.txt';
> # no idea, but command prompt requests this when using mask with 3D data
> set zmap=10.0;
> # file which contains the output
> set output = 'gstat_out.txt';
> set n_uk = 20;
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