[R-sig-Geo] Simulating Two Surfaces with a user-defined Cross-Correlation Index

[Edzer Pebesma]

If the variables are spatially uncorrelated, it is a special case of
what I provided, and you could specify the variography in terms of pure
nuggets, and/or use a neighbourhood of 1 (or 0?).

As an alternative, fill the grids with data generated with function
rmvnorm in package mvtnorm.

I find it however hard to understand what you mean by a spatial
cross-correlation index, especially the word spatial, when you do not
want to address spatial autocorrelation of the variables themselves.
--
Edzer

Enrico R. Crema wrote:
> Many Thanks,
> But I guess explained very badly (sorry for this!!) what I need. I am
> building an Agent Based Simulation and part of the model requires
> series of two randomly generated raster maps, having a spatial
> cross-correlation index ranging from -1 to +1. Clearly If I can
> specify autocorrelation of each that will be even better, but at this
> stage I just need two randomly generated surfaces with a
> user-specified Cross-Correlation Index. Sorry again for the bad
> explanation!
>
> Enrico
>
> ---------------------------------------
> Enrico R. Crema
> PhD Candidate
> Institute of Archaeology, UCL
> AHRC Centre for the Evolution of Cultural Diversity, UCL
> http://www.cecd.ucl.ac.uk/people/?go1=91
> +44 7899093191
> e.crema at ucl.ac.uk
> enrico.crema at gmail.com
>
>
>
>
>
>
>
> On 9 Oct 2009, at 07:49, Edzer Pebesma wrote:
>
>> Enrico, try
>>
>> library(gstat)
>> demo(cosimulation)
>>
>> First part is on Gaussian simulation, the second on indicator
>> simulations.
>>
>> Best regards,
>>
>> Enrico R. Crema wrote:
>>> Dear All,
>>> Is there any R function capable a set of two raster maps with a user-
>>> defined spatial cross-correlation index (between the two rasters)?
>>> Many Thanks,
>>> Enrico Crema
>>> ---------------------------------------
>>> Enrico R. Crema
>>> PhD Candidate
>>> Institute of Archaeology, UCL
>>> AHRC Centre for the Evolution of Cultural Diversity, UCL
>>> http://www.cecd.ucl.ac.uk/people/?go1=91
>>> +44 7899093191
>>> e.crema at ucl.ac.uk
>>> enrico.crema at gmail.com
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>     [[alternative HTML version deleted]]
>>>
>>> _______________________________________________
>>> R-sig-Geo mailing list
>>> R-sig-Geo at stat.math.ethz.ch
>>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>>
>>
>> -- 
>> Edzer Pebesma
>> Institute for Geoinformatics (ifgi), University of Münster
>> Weseler Straße 253, 48151 Münster, Germany. Phone: +49 251
>> 8333081, Fax: +49 251 8339763 http://ifgi.uni-muenster.de/
>> http://www.springer.com/978-0-387-78170-9 e.pebesma at wwu.de
>>
>
>

-- 
Edzer Pebesma
Institute for Geoinformatics (ifgi), University of Münster
Weseler Straße 253, 48151 Münster, Germany. Phone: +49 251
8333081, Fax: +49 251 8339763 http://ifgi.uni-muenster.de/
http://www.springer.com/978-0-387-78170-9 e.pebesma at wwu.de