[R] Reading in a large number of dbf files

[Steve_Friedman at nps.gov]

good morning

This question is not a stats question per say but a data management and
lattice plotting problem.  I apologize now if I'm asking an inappropriate
question to this gracious group.

I'm need to bring in approximately 100 *.dbf files into R but I'm having
difficultly understanding several examples I've tracked down regarding this
procedure and could benefit from your suggestions.

One example I've found does the following:

DF <- lappy(dir(pattern="file.*\\.txt"), read.table, sep=";". header= TRUE)
names(DF)  <- paste("data", seq_along(DF), sep = "")

This solution will not work for me for at least 2 reasons:

1) I need to modify the files after I import them by adding three new
parameters to each file prior to combining them into a common data.frame
 For example one of my files is called SRF_DryDry_stats.dbf.  The name of
the file tells me that it refers to two conditions; 1) SRF = an indictor
region field, and 2) DryDry = dry hydrological conditions. I also know that
the data refer to a particular species.

The data in the file include some general summarizing  statistics (Min,
Max, Range, Mean, and STD). After modifying the file, I need a species
field, the SRF field and the hydro condition parameters in the file.  After
this modification, I need to "cbind" these files into a common file.

2) The goal is to use the common file to produce a series of lattice
barchart graphs using the three new parameters as factors and plotting the
some of the statistics in the lattice call statements.

Is there a clean way of accomplishing these tasks or should the brute force
approach be taken?


Steve Friedman Ph. D.
Spatial Statistical Analyst
Everglades and Dry Tortugas National Park
950 N Krome Ave (3rd Floor)
Homestead, Florida 33034

Steve_Friedman at nps.gov
Office (305) 224 - 4282
Fax     (305) 224 - 4147