[R] Programcode and data in the same textfile

[Prof Brian Ripley]

This is not a valid solution: R does not necessarily have a history 
mechanism operational.  But if it did, you could use history() not
savehistory().

Does no one ever read the help pages?

On Thu, 12 Jun 2003, Ernst Hansen wrote:

> Thomas W Blackwell writes:
>  > Ernst  -
>  > 
>  > Here's a solution which works for me, and seems to do
>  > what you want.  It's a bit of a hack, since it requires
>  > you, the author, to know in advance what file path name
>  > the student will have saved the file as.  In my example,
>  > this will be "./r.source.file", and this includes one
>  > blank line before the first assignment statement below.
>  > 
>  > It also requires knowing how many lines of code precede
>  > the data lines.  But it _is_ a one-file solution, as
>  > requested.  Put the following 9 or 10 lines into a
>  > file named "r.source.file", then source it.
>  > 
>  > data.01 <- read.table(file="r.source.file", header=T,
>  > 	skip=4, comment.char="")[-1]
>  > 
>  >  # junk Sex      Response
>  >     #   Male     1
>  >     #   Male     2
>  >     #   Female   3
>  >     #   Female   4
>  > 
>  > 
>  > I'm quite surprised no one else has suggested this already.
>  > 
> 
> 
> Nice thinking , Thomas, and good fun indeed.  To take this slightly
> further, we can hack the history mechanism to read off the name of the
> file being sourced.  If the following lines
> 
>   MyHistory <- function() {
>     ## basically the first few lines of history()
> 
>     file1 <- tempfile("Rrawhist")
>     savehistory(file1)
>     rawhist <- scan(file1, what = "", quiet = TRUE, sep = "\n")
>     unlink(file1)
>     rawhist[length(rawhist)]
>     }
> 
>   cat(strsplit(strsplit(MyHistory(),
>   'source\\(')[[1]][2],'\\)')[[1]][1], '\n')
> 
> are placed in the file foo.q, then the call
> 
>  source('foo.q')
> 
> will produce as output
> 
>   'foo.q' 
> 
> on the terminal.  Instead of writing it out, it could be piped into
> read.table(), and by careful linecounting, it could be combined with
> your idea of reading lines, that are commented out in the 'real
> reading' of the file.  
> 
> 
> Then it indeed does what I wanted to do.  Though my students would 
> be horrified...:-)
> 
> And, of course, if it is allowed to write the history to a temporary
> file and read it again, we might as well write the data to a temporary
> file, as has already been suggested by Torsten Hothorn.
> 
> Ernst
> 
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-- 
Brian D. Ripley,                  ripley at 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 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595