[R-sig-Geo] Error gstat function krigeST

[Edzer Pebesma]

Dear Francesco, there are several reasons why this could happen. The
first one I would look at is whether you have duplicate observations,
meaning observations that share exactly the same spatial and temporal
coordinate. Let me know if it helped,

On 07/31/2014 05:45 PM, Francesco Tonini wrote:
> Dear all,
> 
> I am working with an hourly dataset of air temperature, recorded at ~200
> stations over a relatively small area. I chose a space-time variogram
> (e.g. sum-metric) to fit my data and am now trying to make predictions
> over my same stations in order to fill NA (missing value) gaps. When
> using the krigeST() function over daily aggregated data everything seems
> to go smooth but when I use it at the original hourly resolution I
> always get the following error:
> 
> Error in chol.default(A)
> the leading minor of order 68 is not positive definite
> 
> I googled it and found that it is related to a matrix not being
> completely positive-definite. However, I am not sure why this happens
> and was wondering if any of you know a way of fixing this (a workaround
> to avoid it).
> 
> Thanks!
> Francesco
> 
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-- 
Edzer Pebesma
Institute for Geoinformatics (ifgi), University of Münster
Heisenbergstraße 2, 48149 Münster, Germany. Phone: +49 251
83 33081 http://ifgi.uni-muenster.de GPG key ID 0xAC227795

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