Learn R Programming

knitr (version 1.15.1)

spin: Spin goat's hair into wool

Description

This function takes a specially formatted R script and converts it to a literate programming document. By default normal text (documentation) should be written after the roxygen comment (#') and code chunk options are written after #+ or #- or # ----.

Usage

spin(hair, knit = TRUE, report = TRUE, text = NULL, envir = parent.frame(), 
    format = c("Rmd", "Rnw", "Rhtml", "Rtex", "Rrst"), doc = "^#+'[ ]?", 
    inline = "^[{][{](.+)[}][}][ ]*$", comment = c("^[# ]*/[*]", "^.*[*]/ *$"), 
    precious = !knit && is.null(text))

Arguments

hair
the path to the R script
knit
logical: whether to compile the document after conversion
report
logical: whether to generate report for Rmd, Rnw and Rtex output (ignored if knit = FALSE)
text
a character vector as an alternative way to hair to provide the R source; if text is not NULL, hair will be ignored
envir
the environment for knit() to evaluate the code
format
character: the output format (it takes five possible values); the default is R Markdown
doc
a regular expression to identify the documentation lines; by default it follows the roxygen convention, but it can be customized, e.g. if you want to use ## to denote documentation, you can use '^##\\s*'
inline
a regular expression to identify inline R expressions; by default, code of the form ((code)) on its own line is treated as an inline expression
comment
a pair of regular expressions for the start and end delimiters of comments; the lines between a start and an end delimiter will be ignored; by default, the delimiters are /* in the beginning and */ in the end of a line (following the convention of C comments)
precious
logical: whether intermediate files (e.g., .Rmd files when format is "Rmd") should be preserved; default FALSE if knit == TRUE and input is a file

Value

If text is NULL, the path of the final output document, otherwise the content of the output.

Details

Obviously the goat's hair is the original R script, and the wool is the literate programming document (ready to be knitted).

References

http://yihui.name/knitr/demo/stitch/

See Also

stitch (feed a template with an R script)

Examples

Run this code
#' write normal text like this and chunk options like below

#+ label, opt=value

# /*
#' these lines are treated as comments in spin()
1 + 1
# */

(s = system.file("examples", "knitr-spin.R", package = "knitr"))
spin(s)  # default markdown
o = spin(s, knit = FALSE)  # convert only; do not make a purse yet
knit2html(o)  # compile to HTML

# other formats
spin(s, FALSE, format = "Rnw")  # you need to write documentclass after #'
spin(s, FALSE, format = "Rhtml")
spin(s, FALSE, format = "Rtex")
spin(s, FALSE, format = "Rrst")

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