Hello all,

This is my first posting to R-sig-geo; I looked for the answer in the archives, but have not had any luck for my particular question. 

I have a newbie question about the correspondence between gstat and ArcGIS.  I have a problem that gives very very satisfying results in ArcGIS, and I would like to write a public function in R for others to use that does the same thing.  The choice I used in Arc was "Universal" and in the dropdown menu it says "Linear with Linear Drift".  My data matrix is pretty standard:  2000 x 2000, with some NA, and values between 0 and 255.

So I have a few questions.  Maybe I'll enumerate them.
1. Has anyone made a comprehensive list between ArcGIS functionality and how to do it in gstat?

2. If not: does anyone know a simple correspondence between what ArcGIS is doing and how to set up a gstat call for "Universal/Linear with Linear Drift"?  I have looked online for precise details about Arc's behavior, but haven't seen anything detailed enough.

3. Are there any tricks in gstat that make interpolation with gstat especially fast or slow?  For example, if the numbers were treated faster if they were between 0 and 1, or if NA should be recoded, or if I should never use a data frame but always a matrix.  That sort of thing.

If not, I'll resort to trial and error and diving deeper into the gstat documentation.  But it seems like a good idea to check in first.  For anyone interested, I am trying to repair Landsat satellite photos, which have big broken strips of nodata due to a mechanical failure.  The strips are up to 14 pixels wide.  I need to do this 2000x2000 interpolation about 2000 times-- so speed differences of even a few seconds or minutes are quite important..

Thanks!
Jeff

------------------------------------------
Prof. Jeffrey Cardille
jeffrey.cardille@umontreal.ca

******************************************************************************************
**  http://www.geog.umontreal.ca :                Web                                   **
**  http://sites.google.com/site/jeffcardille :   Plans de Cours et Recherche           **
**                                                                                      **
**  "Petit à petit l'oiseau fait son nid ..."    N'hésitez pas à corriger mon français  **
*********************************************************************************************************
**     Département de Géographie                        **     Bureau:                                 **
**     assistant professor / professeur adjoint         **     Salle 440                               **
**     Université de Montréal                           **     Pavillon Strathcona                     **
**     C.P. 6128                                        **     520, chemin de la Côte-Ste-Catherine    **
**     Succursale Centre-ville                          **     Montreal, QC H2V 2B8                    **
**     Montréal, QC, H3C 3J7                            **     Télé: (514) 343-8003                    **
*********************************************************************************************************
**
**  Pour aider à Haiti avec votre intérêt de géographie, visitez:
**  http://groups.google.com/group/udem-geo-aide/
**
*********************************************************************************************************





	[[alternative HTML version deleted]]

