Hi All,


I'm fitting variograms in GSTAT with fit.variogram. The coordinates are in
UTM  (meters) and I got the Warning message: *singular model in variogram
fit*.

I found the reason from a previous archive mail of this warning message. (
http://www.mail-archive.com/r-sig-geo@stat.math.ethz.ch/msg04054.html)


Basically one possible solution is to divide the UTM coordinates (meters) by
1000 to convert them in km.

But I really do not want to go back to excel to convert the coordinates
values. I would like to use R for doing this operation on the coordinates.


My questions are:



   1. Can this division take place directly on the SpatialPontsDataFrame or
   it should first be done on the dataframe?
   2. How do I do this division to the concerned column? Using the
   fix(dataframe) or edit.row.names  will take me ages and is not a
   solution.


Thanks for your Helps


The structure of the data I'm using:


Formal class 'SpatialPointsDataFrame' [package "sp"] with 5 slots

  ..@ data       :'data.frame':   2433 obs. of  10 variables:

  .. ..$ CODAGIS: num [1:2433] 1201038 1501545 1471560 1101438 1267741 ...

  .. ..$ COND   : num [1:2433] 10 10 13 14 14 17 17 18 19 19 ...

  .. ..$ litho2 : Factor w/ 14 levels "Bg","Bp","Bs",..: 10 10 11 3 10 10 10
11 11 11 ...

  .. ..$ targ   : num [1:2433] 194 233 218 252 217 ...

  .. ..$ tseas  : num [1:2433] 1192 2445 2077 2746 1928 ...

  .. ..$ amt    : num [1:2433] 285 276 269 292 282 ...

  .. ..$ amprc  : num [1:2433] 778 965 1083 632 847 ...

  .. ..$ qscond : Factor w/ 4 levels "[10,300]","(300,450]",..: 1 1 1 1 1 1
1 1 1 1 ...

  ..@ coords.nrs : int [1:2] 4 5

  ..@ coords     : num [1:2433, 1:2] 300199 466229 270440 251040 343761 ...

  .. ..- attr(*, "dimnames")=List of 2

  .. .. ..$ : NULL

  .. .. ..$ : chr [1:2] "XUTM" "YUTM"

  ..@ bbox       : num [1:2, 1:2] 155702 1331253 534504 1719735

  .. ..- attr(*, "dimnames")=List of 2

  .. .. ..$ : chr [1:2] "XUTM" "YUTM"

  .. .. ..$ : chr [1:2] "min" "max"

  ..@ proj4string:Formal class 'CRS' [package "sp"] with 1 slots

  .. .. ..@ projargs: chr "+proj=utm +zone=29 +datum=WGS84"




-- 
Mit freundlichen Grüßen / Kind regards / Meilleures Salutations


Eric Böker

Hydrogéologue
Chef Projet PMRE
Hippodrome
Rue 326, Porte 21
BP 701 BAMAKO (MALI)
Cell: (00223) 766 87 477
e-mail: eric.boeker@gmail.com

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