[R-sig-Geo] predict() LDL error

[Edzer Pebesma]

to remove duplicates in DF you need to replace it:

DF = remove.duplicates(DF, zero=0, remove.second = TRUE)
zerodist(DF)

On 07/15/2011 10:23 AM, Matevž Pavlič wrote:
> Hi, thanks for your time....
> 
> I am sure the problem is in same locations...but i dont know why remove.duplicates() does not remove duplicates... 
> When i try this :
> 
>> coordinates(DF)<-~X+Y
>> zerodist(DF)
>      [,1] [,2]
> [1,]   83   84
> [2,]  242  243
> [3,]  266  267
> [4,]  431  432
> [5,]  439  440
> [6,]  731  732
> [7,]  817  818
> [8,]  820  821
> 
>> remove.duplicates(DF, zero=0, remove.second = TRUE)
> ...
> 1113 (99447.1, 459012)     7019   290.17   286.57      6
> 1114 (99465.2, 458975)     7022   291.97   287.27      0
> 1115   (99410, 458997)     7015   291.04   288.74      6
> 1116   (99495, 458978)     7016   290.62   288.72      6
> 1117 (99438.3, 458992)     7018   291.28   288.38      6
> 1118   (99813, 458891)     7021   290.08   285.58      0
> 
>> zerodist(DF)
>      [,1] [,2]
> [1,]   83   84
> [2,]  242  243
> [3,]  266  267
> [4,]  431  432
> [5,]  439  440
> [6,]  731  732
> [7,]  817  818
> [8,]  820  821
> 
> it stays the same...shouln't it remove the duplicates?
> 
> 
> thanks, m
> 
> -----Original Message-----
> From: r-sig-geo-bounces at r-project.org [mailto:r-sig-geo-bounces at r-project.org] On Behalf Of Edzer Pebesma
> Sent: Thursday, July 14, 2011 11:25 PM
> To: r-sig-geo at r-project.org
> Subject: Re: [R-sig-Geo] predict() LDL error
> 
> The error message is an indication that you're predicting (kriging) with a singular covariance matrix. The most frequent reasons for this are duplicate observations [1] or perfect correlation in the coregionalization model [2]. For [1], see ?remove.duplicates, for [2] see argument correct.diagonal in ?fit.lmc.
> 
> On 07/14/2011 06:18 PM, Matevž Pavlič wrote:
>> Hi all,
>>
>>  
>>
>> i am trying to use categorical kriging for prediction of soil classes in an area. I am pretty new to using cat. kriging in R soI probably am making some beginers mistakes. Attached is a reproducable sample with sample data. 
>>
>>  
>>
>> When i try to use predict() i geta n error- I am pretty sure because some points are duplicated....in krige() function i use zerodist() which eliminates the LDL error, but i can't find a way to use it here....
>>
>>  
>>
>> I got this code (mostly) from the net, so i have some trouble understanding it...
>>
>>  
>>
>> thanks for any help and info about categorical kriging,
>>
>>  
>>
>> m
>>
>>  
>>
>>
>>
>>
>>
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> 
> --
> 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.52north.org/geostatistics      e.pebesma at wwu.de
> 
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-- 
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.52north.org/geostatistics      e.pebesma at wwu.de