[R] Reading in a large number of dbf files

[jim holtman]

A process like the following is how I would do it:

inputData <- lapply(listOfFiles, function(.file){
    input <- read.table(.file, ....whatever other parameters...)
    # now do the modifications that you need
    ....
    input  # return the updated dataframe
})

# combine into one dataframe
inputData <- do.call(rbind, inputData)


On Thu, Apr 16, 2009 at 10:35 AM,  <Steve_Friedman at nps.gov> 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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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>



-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?