Reading in a large number of dbf files

Duncan,

Thank  you very much. I did not have a chance to examine this approach
today. I will because I need to have this functionality.

I appreciate you time and insights

Steve

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


                                                                           
             Duncan Mackay                                                 
             <mackay at northnet.                                             
             com.au>                                                    To 
                                       Steve_Friedman at nps.gov              
             04/17/2009 09:05                                           cc 
             AM ZE10                   r-help at r-project.org                
                                                                   Subject 
                                       Re: [R] Reading in a large number   
                                       of dbf files                        
                                                                           
                                                                           
                                                                           
                                                                           
                                                                           
                                                                           




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

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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