citation(package = "base", lib.loc = NULL, auto = NULL)
readCitationFile(file, meta = NULL)
NULL
. The default value of NULL
corresponds to all
libraries currently known. If the default is used, the loaded
packages are searched before the libraries.DESCRIPTION
metadata should
be used or not, or NULL
(default), indicating that a
CITATION
file is used if it exists, or an object of class
"packageDescription"
with package metadata (see
below).packageDescription
, or NULL
(the default)."bibentry"
.citation()
for information on how to cite the
base R system in publications. If the name of a non-base package is
given, the function either returns the information contained in the
CITATION
file of the package or auto-generates citation
information. In the latter case the package DESCRIPTION
file
is parsed, the resulting citation object may be arbitrarily bad, but
is quite useful (at least as a starting point) in most cases. In R >= 2.14.0, one can use a Authors@R field in
DESCRIPTION
to provide (R code giving) a
person
object with a refined, machine-readable
description of the package “authors” (in particular specifying
their precise roles). Only those with an author role will be
included in the auto-generated citation. If only one reference is given, the print method for the object
returned by citation()
shows both a text version and a BibTeX
entry for it, if a package has more than one reference then only the
text versions are shown. The BibTeX versions can be obtained using
function toBibtex()
(see the examples below). The CITATION
file of an R package should be placed in the
inst
subdirectory of the package source. The file is an R
source file and may contain arbitrary R commands including
conditionals and computations. Function readCitationFile()
is
used by citation()
to extract the information in
CITATION
files. The file is source()
ed by the R
parser in a temporary environment and all resulting bibliographic
objects (specifically, of class "bibentry"
) are
collected. Traditionally, the CITATION
file contained zero or more calls
to citHeader
, then one or more calls to citEntry
,
and finally zero or more calls to citFooter
, where in fact
citHeader
and citFooter
are simply wrappers to
paste
, with their …
argument passed on to
paste
as is. The "bibentry"
class
makes for improved representation and manipulation of bibliographic
information (in fact, the old mechanism is implemented using the new
one), and one can write CITATION
files using the unified
bibentry
interface. One can include an auto-generated package citation in the
CITATION
file via citation(auto = meta)
. readCitationFile
makes use of the Encoding
element (if
any) of meta
to determine the encoding of the file.bibentry
## the basic R reference
citation()
## references for a package -- might not have these installed
if(nchar(system.file(package = "lattice"))) citation("lattice")
if(nchar(system.file(package = "foreign"))) citation("foreign")
## extract the bibtex entry from the return value
x <- citation()
toBibtex(x)
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