Sweave

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Sweave

• Adele Cutler

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Sweave

• Friedrich Leisch
• Department of Statistics
• Ludwig-Maximilians-Universität München
• http//www.statistik.lmu.de/leisch/

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What is Sweave?

• Sweave is a framework for mixing
• high quality typesetting (LaTeX)
• code (R)
• graphs/tables/output
• so that the report can be automatically
  re-created when the results or methodology
  change.

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How Sweave Works

• The author writes an Sweave file, an ordinary
  text file ending in SNW, containing
• chunks of R
• chunks of LaTeX
• bits of glue that control everything
• Sweave creates a LaTeX file with the R code
  replaced, if desired, by its output.
• Stangle creates a file with just the R code
  (ready to be run in R).

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Example

• Create an Sweave file called small.SNW and go
  into R.
• The R command
• Sweave(small.SNW)
• produces a new file called small.SNW.tex.
• We can now run LaTex in the usual way.
• The R command
• Stangle(small.SNW)
• produces a new file called small.SNW.R.
• We could execute these commands using
• source(small.SNW.R)
• from inside R.

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Sweave
Small.SNW
Sweave()
Stangle()
Small.SNW.R
Small.SNW.tex
LaTeX with R results
R commands only
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Writing Sweave Files (_Snw)

• LaTeX chunks start with _at_ and are just standard
  LaTeX.
• To include scalars in text, use \Sexprexpr,
  where expr is an R expression returning a vector,
  the first element of which will be printed in the
  LaTeX.

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Writing Sweave Files (continued)

• R chunks start with ltltnamegtgt
• Global options can be added using
• \SweaveOptsopt1val1,,optnvaln
• anywhere in a LaTeX chunk.
• Options can be added to a single R chunk using
• ltltname,opt1val1,,optnvalngtgt

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Useful Options

• echoFALSE prevents the R code from showing up in
  the LaTeX file.
• figTRUE creates EPS and PDF files corresponding
  to the plots and inserts the relevant command
  into the LaTeX file.
• resultshide
• evalfalse

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Named R chunks

• R chunks can be named and reused
• ltltagtgt
• x10
• _at_
• ltltbgtgt
• xy
• _at_
• ltltcgtgt
• ltltagtgt
• y20
• ltltbgtgt
• _at_

Is equivalent to ltltcgtgt x10 y20 xy _at_
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For More Information

• Read the FAQ
• http//www.statistik.lmu.de/leisch/Sweave/FAQ.htm
  l
• Read the Manual
• http//www.statistik.lmu.de/leisch/Sweave/Sweave-
  manual.pdf