CountColumns: count columns of files

In MultiJoin: Enables Efficient Joining of Data File on Common Fields using the Unix Utility Join

Description

small helper function that attempts to count how many columns there are in a file

Usage

CountColumns(files = c("ftr1.txt", "ftr2.txt"), sep = c(" ", 


    ",", "\t", "|")[1], mycat = c("", "gunzip -cf ", "cat ")[1], 


    filterStr = "", verbose = 0, ...)

Arguments

files	which files to inspect
sep	column delimiter; default white space
mycat	effective cat command, if empty do NOT use FIFos
filterStr	various inline filters that act locally and do not need an input file,
verbose	level of verbosity
...	further arguments to myjoin such as missingValue or extraARGS

Value

returns number of columns of each file

Author(s)

"Markus Loecher, Berlin School of Economics and Law (BSEL)" <[e-mail]>

Examples

if (0){


  ret = ArtificialData(fakeDataDir="fakeData2", joinKey = 0:9, N = rep(6, 4), verbose=1)


  CountColumns(paste0("fakeData2/file",1:4,".txt"))


  #gzipped data:


  ret = ArtificialData(fakeDataDir="fakeData2", joinKey = 0:9, N = rep(6, 4), GZIP=1, verbose=1)


  CountColumns(paste0("fakeData2/file",1:4,".txt.gz"),mycat ="gunzip -cf ")


  #gzipped and selected columns:  


  ret = ArtificialData(fakeDataDir="fakeData2", joinKey = 0:9, N = rep(6, 4), GZIP=1, verbose=1)


  CountColumns(paste0("fakeData2/file",1:4,".txt.gz"),mycat ="gunzip -cf ", 


               filterStr=" | cut -f1,3 -d\" \" ")


}

MultiJoin documentation built on May 1, 2019, 7:32 p.m.