Thanks Gabor. I made the column names look like as:
probeset WM806SignalA WM806call WM1716SignalA WM1716call .... And I then tried what you mentioned and got: > library(sqldf) Loading required package: gsubfn Loading required package: proto > source("http://sqldf.googlecode.com/svn/trunk/R/sqldf.R") > myfile <- file("243_47mel_withnormal_expression_log2.txt") > stmt <- read.table(myfile, nr = 1, as.is = TRUE) > stmt <- stmt[regexpr("call", stmt) < 0] > stmt <- paste("select", paste(stmt, collapse = ","), "from myfile") > DF <- sqldf(stmt, file.format = list(sep = " ")) Error in summary.connection(get(fo, envir)) : invalid connection > How should I correct this? Thanks! Allen On Nov 10, 2007 1:11 AM, Gabor Grothendieck <[EMAIL PROTECTED]> wrote: > On Nov 10, 2007 12:25 AM, affy snp <[EMAIL PROTECTED]> wrote: > > Hi Gabor, > > > > Thanks a lot! > > > > The header of the big file looks like as follows: > > > > probe_set > > WM_806_Signal_A > > WM_806_call > > WM_1716_Signal_A > > WM_1716_call > > .... > > > > I only need those columns with the header as like _Signal_A > > > > Can you suggest how to use sqldf? > > > > sqlite requires that a single character separate the fields. Use sed or > other method to reduce multiple spaces to one space in the input > file and then try something like this: > > library(sqldf) > source("http://sqldf.googlecode.com/svn/trunk/R/sqldf.R") > > # get headings > myfile <- file("myfile.dat") > stmt <- read.table(myfile, nr = 1, as.is = TRUE) > > # assume any column with call in its name is to be eliminated > # and form select statement > stmt <- stmt[regexpr("call", stmt) < 0] > stmt <- paste("select", paste(stmt, collapse = ","), "from myfile") > > # run it > myfile <- file("myfile.dat") > DF <- sqldf(stmt, file.format = list(sep = " ")) > ______________________________________________ R-help@r-project.org 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.