[R] Reading in a large number of dbf files

[Duncan Mackay]

Steve

If the .dbf extension files are dBase type.
generalizing: there are 2 series of dbase .dbf files for non SQL type dbf 
files:
1  dBase III when Borland had dBase and
2  dBase 2000 produced by dBase inc

If they are dbase III (ie can be imported into Excel) you can use the 
foreign package to import them

require(foreign)
# get a list of files
listd <- list.files(.....)

# loop or otherwise
for (j in seq_along(lisd) ) {

    # Example for 1 file (you will have to use something different for > 1)
    x <-   read.dbf(list[j], as.is = TRUE)

}

Regards

Duncan Mackay
Department of Agronomy and Soil Science
University of New England
ARMIDALE NSW 2351
Email home: mackay at northnet.com.au

At 00:35 17/04/2009, you wrote:

>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
>
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