[R-sig-Geo] Weird experimental 3D spatiotemporal variogram

[Benedikt Gräler]

Dear Piero,

how did you compute these variograms, using variogramST in gstat (which 
version?)?

Figures 4-7 in gstat's vignette "Spatio-temporal geostatistics using 
gstat" on CRAN show the missing value for the zero temporal and zero 
spatial lag class. I could not identify this property in your wireframe 
plots.

To me, the temporal effect looks like being "upside-down". I'll be happy 
to take a quick look at your script/data in case your problem still 
remains.

Best,

  Ben



On 15.01.2013 11:51, Edzer Pebesma wrote:
> Piero,
>
> from the orientation of your graph, I could not see very well what
> happens at zero-time, zero-space lag.
>
> Did you compute a pure-time variogram, i.e. with zero space distance?
> This one should have a missing zero-value, unless you have duplicate
> measurements.
>
> On 01/10/2013 03:20 PM, Piero Campalani wrote:
>> Dear list,
>>
>> I am predicting PM measurements on a spatiotemporal grid with monthly
>> intervals in time.
>> At modeling time, I am looking at the experimental 3D variograms
>> (`wireframes`) but I see that weird decreasing behavior in time (see
>> wireframes_2008-1.eps for January 2008): there is a peak at 0 time lags,
>> then correlation in time is much higher over different days.
>> How can I interpret such variogram?
>> Would it mean that there is a very high spatial variability for values on
>> the same day, whereas temporal variability is significantly lower?
>>
>> Thanks for any hint,
>> (I can provide implementation details in case of need)
>>
>> Piero
>>
>>
>>
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>>
>

-- 
Benedikt Gräler

ifgi - Institute for Geoinformatics
University of Muenster

http://ifgi.uni-muenster.de/graeler

Phone: +49 251 83-33082
Mail: ben.graeler at uni-muenster.de