I know you would prefer a 100% R solution but using the unix cut command (a Windows version is available in tools.zip at: http://www.murdoch-sutherland.com/Rtools/ ) is really easy. Maybe if you preprocessed it with that you could then use read.fwf.
For example, look how easy it was to cut this file down to half extracting columns 2-3 and 6-8: C:\bin>type a.dat 123456789 123456789 123456789 C:\bin>cut -c2-3,6-8 a.dat 23678 23678 23678 On 9/13/06, Anupam Tyagi <[EMAIL PROTECTED]> wrote: > Barry Rowlingson <B.Rowlingson <at> lancaster.ac.uk> writes: > > > > > None of these seem to read non-coniguous variables from columns; or > > > may be I am missing something. "read.fwf" is not meant for large > > > files according to a post in the archives. Thanks for the pointers. I > > > have read the R data input and output. Anupam. > > > > First up, how 'large' is your 'large ASCII file'? How many rows and > > columns? > > There are 356,112 records, 326 variables, fixed record length of 1283 > positions. > Zipped file is 42MB. There are no field (variable) separaters (delimiters). > > > Secondly, what are 'non-contiguous' variables? > > Variables that are not in adjoining positions in the file: reading them from > the > file would require skipping columns while reading. For example, below are the > start positions of the first three variables I would like to read. > > StartingColumn VariableName FieldLength > 1 STATE 2 > 24 INTVID 3 > 30 PSU 10 > > > > Perhaps if you posted the first few lines and columns of the file then > > we might get an idea of how to read it in. > > Because a record (row) of the file is 1283 columns, I would not like to post > it > here. > > Thank you for your response. > > Anupam. > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
