Both will work if you copy and paste directly into an R session but textConnection has the advantage that you can place it in a file and source it and it still works.
On Sat, Jul 11, 2009 at 4:38 PM, Muenchen, Robert A (Bob) <muenc...@utk.edu>wrote: > Dear R-helpers, > > I know of two ways to reading data within an R program, using > textConnection and stdin (demo program below). I've Googled about and > looked in several books for comparisons of the two approaches but > haven't found anything. Are there any particular advantages or > disadvantages to these two approaches? If you were teaching R beginners, > which would you present? > > Thanks, > Bob > http://RforSASandSPSSusers.com > > > # R Program to Read Data Within a Program. > # Very similar to SAS datalines or cards statements, > # and SPSS BEGIN DATA / END DATA commands. > > # This stores the data as one long text string. > > mystring <- > "workshop,gender,q1,q2,q3,q4 > 01,1,f,1,1,5,1 > 02,2,f,2,1,4,1 > 03,1,f,2,2,4,3 > 04,2, ,3,1, ,3 > 05,1,m,4,5,2,4 > 06,2,m,5,4,5,5 > 07,1,m,5,3,4,4 > 08,2,m,4,5,5,5" > > # The textConnection function allows read.csv to > # read data from the text string just as it would > # from a file. > # The leading zero on first column helps show that > # R is storing row names as a character vector. > > mydata <- read.csv( textConnection(mystring) ) > mydata > > > mydata <- read.csv( stdin() ) > workshop,gender,q1,q2,q3,q4 > 01,1,f,1,1,5,1 > 02,2,f,2,1,4,1 > 03,1,f,2,2,4,3 > 04,2, ,3,1, ,3 > 05,1,m,4,5,2,4 > 06,2,m,5,4,5,5 > 07,1,m,5,3,4,4 > 08,2,m,4,5,5,5 > > #The blank line above tells R to stop reading. > mydata > > # Read it again stripping out blanks and setting > # "nothing" to be missing for gender. > > mydata <- read.csv( stdin(), strip.white=TRUE, na.strings="" ) > workshop,gender,q1,q2,q3,q4 > 01,1,f,1,1,5,1 > 02,2,f,2,1,4,1 > 03,1,f,2,2,4,3 > 04,2, ,3,1, ,3 > 05,1,m,4,5,2,4 > 06,2,m,5,4,5,5 > 07,1,m,5,3,4,4 > 08,2,m,4,5,5,5 > > mydata > > ______________________________________________ > 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. > [[alternative HTML version deleted]] ______________________________________________ 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.
