This function converts an Sweave document to a knitr-compatible document.
Sweave2knitr(
file,
output = gsub("[.]([^.]+)$", "-knitr.\1", file),
text = NULL
)If text is NULL, the output file is written and
NULL is returned. Otherwise, the converted text string is returned.
Path to the Rnw file (must be encoded in UTF-8).
Output file path. By default, file.Rnw produces
file-knitr.Rnw); if text is not NULL, no output file will be
produced.
An alternative way to provide the Sweave code as a character
string. If text is provided, file will be ignored.
The pseudo command \SweaveInput{file.Rnw} is converted to a code
chunk header <<child='file.Rnw'>>=.
Similarly \SweaveOpts{opt = value} is converted to a code chunk
opts_chunk$set(opt = value) with the chunk option include =
FALSE; the options are automatically fixed in the same way as local chunk
options (explained below).
The Sweave package \usepackage{Sweave} in the preamble is removed because it is not required.
Chunk options are updated if necessary: option values true and
false are changed to TRUE and FALSE respectively;
fig=TRUE is removed because it is not necessary for knitr (plots
will be automatically generated); fig=FALSE is changed to
fig.keep='none'; the devices pdf/jpeg/png/eps/tikz=TRUE are
converted to dev='pdf'/'jpeg'/'png'/'postscript'/'tikz';
pdf/jpeg/png/eps/tikz=FALSE are removed;
results=tex/verbatim/hide are changed to
results='asis'/'markup'/'hide'; width/height are changed to
fig.width/fig.height; prefix.string is changed to
fig.path; print/term/prefix=TRUE/FALSE are removed; most of the
character options (e.g. engine and out.width) are quoted;
keep.source=TRUE/FALSE is changed to tidy=FALSE/TRUE (note the
order of values).
If a line @ (it closes a chunk) directly follows a previous
@, it is removed; if a line @ appears before a code chunk and
no chunk is before it, it is also removed, because knitr only uses one
@ after <<>>= by default (which is not the original Noweb
syntax but more natural).
The motivation of the changes in the syntax: https://yihui.org/knitr/demo/sweave/
Sweave2knitr(text = "<>=") # this is valid
Sweave2knitr(text = "<>=") # dev='png'
Sweave2knitr(text = "<>=")
Sweave2knitr(text = "<<,png=false,fig=TRUE>>=")
Sweave2knitr(text = "\\SweaveOpts{echo=false}")
Sweave2knitr(text = "\\SweaveInput{hello.Rnw}")
# Sweave example in utils
testfile = system.file("Sweave", "Sweave-test-1.Rnw", package = "utils")
Sweave2knitr(testfile, output = "Sweave-test-knitr.Rnw")
if (interactive()) knit("Sweave-test-knitr.Rnw") # or knit2pdf() directly
unlink("Sweave-test-knitr.Rnw")
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