R-4.1.2.tar.gz

Sweave User Manual

Friedrich Leisch and R-core

November 1, 2021

1 Introduction

Sweave provides a flexible framework for mixing text and R code for automatic document

generation. A single source file contains both documentation text and R code, which are then

woven into a final document containing

• the documentation text together with

• the R code and/or

1

usually used for literate programming Knuth (1984). Hence, the full power of L

quality typesetting) and R (for data analysis) can be used simultaneously. See Leisch (2002)

and references therein for more general thoughts on dynamic report generation and pointers to

other systems.

Sweave uses a modular concept using different drivers for the actual translations. Obviously

different drivers are needed for different text markup languages (L

T

X, HTML, . . . ). Several

by a space or newline character. The rest of this line is a comment and ignored. Typically

documentation chunks will contain text in a markup language like L

A

T

E

X. The chunk

continues until a new code or documentation chunk is started: note that Sweave does not

interpret the contents of documentation chunks, and so will identify chunk indicators even

inside L

A

T

noweb file. Multiple code chunks can have the same name, the corresponding code chunks are

the concatenated when the source code is extracted. noweb has some additional mechanisms

to cross-reference code chunks (the [[...]] operator, etc.), Sweave does currently not use nor

support these features, so they are not described here.

3 Sweave files

3.1 A simple example

Sweave source files are noweb files with some additional syntax that allows some additional

control over the final output. Traditional noweb files have the extension ‘.nw’, which is also

E

translates this into the L

T

X document shown in Figures 2 and 3. The latter can also be created

E

file ‘Sweave.sty’ is automatically loaded, which provides environments for typesetting R input

and output (the L

chunks are copied without any modification from ‘example-1.Rnw’ to ‘example-1.tex’.

The real work of Sweave is done on the code chunks: The first code chunk has no name, hence

the default behavior of Sweave is used, which transfers both the R commands and their respective

output to the L

T

A

E

the choice of file names for figures follow later in this manual).

• Option echo=FALSE indicates that the R input should not be included in the final document

(no Sinput environment).

Figure 1: A minimal Sweave file: ‘example-1.Rnw’.