[R-sig-Geo] converting old sp objects

[Duncan Golicher]

Thanks. No problem, I use GRASS and was converting them using rgrass6. I 
just hoped there was an even simpler way. I had missed the posting on 
the change, but realised more or less what was going on a few days ago 
when I upgraded.

Duncan

Roger Bivand wrote:

>On Fri, 27 Oct 2006, Duncan Golicher wrote:
>
>  
>
>>I have quite a number of SpatialGridDataFrame objects that were saved 
>>internally under R 2.3.0 and sp0.8-16.  Can anyone suggest a quick and 
>>easy way to convert them for use with R2.4.0 and sp0.9-2. (I do have 
>>ways, but they are all a bit longwinded).
>>    
>>
>
>The issue was announced on this list on 28 September:
>
>https://stat.ethz.ch/pipermail/r-sig-geo/2006-September/001354.html
>
>and has been on the Rgeo site since about the same time.
>
>The major issue is that the way new-style classes (and objects belonging 
>to those classes) are defined internally, so the internal (*.RData) 
>representations are not compatible.
>
>To transfer from the old internal form, use R < 2.4.0, and sp < 0.9 to for 
>example export column by column to GRASS, and then read back in in R >= 
>2.4.0 and sp >= 0.9. Alternatively for non-GRASS users, rgdal and the 
>GTiff fotmat could be used (and should work with multiple bands). The 
>writeAsciiGrid() function in maptools could also be used. There is no way 
>of upgrading the serialised object from the *.RData form directly. 
>
>We know that this is an unfortunate incompatibility, but the changes in 
>the methods package are being made to improve class/object handling, 
>making the software faster and more robust, so the difficulties are 
>unavoidable. For critical projects already using R < 2.4.0, I suggest only 
>upgrading when sensible.
>
>Roger
>
>  
>
>>Thanks,
>>
>>Duncan
>>
>>
>>    
>>
>
>  
>


-- 
Dr Duncan Golicher
Ecologia y Sistematica Terrestre
Conservación de la Biodiversidad
El Colegio de la Frontera Sur
San Cristobal de Las Casas, 
Chiapas, Mexico

Email: dgoliche at sclc.ecosur.mx 

Tel: 967 674 9000 ext 1310
Fax: 967 678 2322

United Kingdom Skypein; 020 7870 6251
Skype name: duncangolicher