Telford Tendys
2000-May-23 01:26 UTC
[Rd] Suggestion for comments in data files (i.e. read.table)
I realise that there is an existing system for documenting datasets but what I would like is to be able to whack a few lines of commentary at the top of a file which contains data -- not full documentation but just an outline for myself to remind me of what I was doing or what settings I was using, etc. I was thinking that the read.table() function might be extended to support an option allowing it to throw away lines that begin with the # character (same comment character as R source, shell script, perl, etc) thus allowing data files with comments added to them. For example: ------------------------------------->8--- # Testing the force of my linear motor # v = supply voltage (reading from built-in meter on bench supply) # x = distance of movement (NA indicates that bar was dropped) # m = mass of bar "v" "x" "m" 1 2 3 4 5 6 7 8 9 # I might have bumped the table for this one 10 NA 12 etc... ------------------------------------->8--- Then you can load it up with: mytable <- read.table( "data", header=TRUE, comment=TRUE ) and then proceed as normal. I'm sure it would be a very small change, if other people think it might be useful then I'll try and make a patch to support it. - Tel -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-devel-request@stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
Prof Brian D Ripley
2000-May-23 06:05 UTC
[Rd] Suggestion for comments in data files (i.e. read.table)
On Tue, 23 May 2000, Telford Tendys wrote:> I realise that there is an existing system for documenting datasets > but what I would like is to be able to whack a few lines of commentary > at the top of a file which contains data -- not full documentation but > just an outline for myself to remind me of what I was doing or what > settings I was using, etc. > > I was thinking that the read.table() function might be extended to > support an option allowing it to throw away lines that begin with > the # character (same comment character as R source, shell script, perl, etc) > thus allowing data files with comments added to them. For example: > > ------------------------------------->8--- > # Testing the force of my linear motor > # v = supply voltage (reading from built-in meter on bench supply) > # x = distance of movement (NA indicates that bar was dropped) > # m = mass of bar > "v" "x" "m" > 1 2 3 > 4 5 6 > 7 8 9 > # I might have bumped the table for this one > 10 NA 12 > > etc... > ------------------------------------->8--- > > Then you can load it up with: > > mytable <- read.table( "data", header=TRUE, comment=TRUE ) > > and then proceed as normal. > > I'm sure it would be a very small change, if other people think > it might be useful then I'll try and make a patch to support it.I am sure it is not `a very small change', I'm afraid. Basically, input is not done in a line-oriented way. read.table uses scan and count.fields. Both are internal functions that work at a char-by-char level. You will need to add logic to skip lines, and for your rule that means adding logic to know that # is first in a line. My suggestion would be to allow # anywhere on the line to skip the rest of the line, and to make sure that # inside quotes did nothing. -- Brian D. Ripley, ripley@stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272860 (secr) Oxford OX1 3TG, UK Fax: +44 1865 272595 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-devel-request@stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
Prof Brian Ripley
2000-May-23 10:56 UTC
[Rd] Suggestion for comments in data files (i.e. read.table)
> From: "Jens Oehlschlägel-Akiyoshi" <jens.oehlschlaegel-akiyoshi@mdfactory.de> > Date: Tue, 23 May 2000 10:40:25 +0200[...]> for Prof. Ripley's suggestion > > > My suggestion would be to allow # anywhere on the line to skip the > > rest of the line, and to make sure that # inside quotes did nothing. > > Final comment: any solution having # skip the rest of the line MUST be > optional, otherwise R looses it's ability to > import general ASCII-data. You never know whether some people use special > characters in their strings.Yes, Telford Tendys had comment=FALSE as the default for that argument. -- Brian D. Ripley, ripley@stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272860 (secr) Oxford OX1 3TG, UK Fax: +44 1865 272595 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-devel-request@stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._