[R-sig-Geo] read shapefile, iterate through rows in attribute table, update attribute table

[Murray Richardson]

Hello users,

I am using R to create some scripts that involve a combination of SAGA 
functions (via RSAGA) and R processes. I need to read a polygon 
shapefile into R, interate through each polygon feature in the attribute 
table, convert it to its own shapefile, and do some processing on that 
individual polygon shapefile in SAGA.  I will then need to update the 
row's attributes (in the original shapefile) with the results of the 
SAGA process. 

I'm primarily looking on advice on how to read and iterate through the 
shapefile rows, converting each one into a temporary shapefile.  I also 
appreciate advice on updating records in a shapefile attribute table. 

Thanks in advance.

Murray Richardson