Add one or more subject terms to the dataset's metadata.
Usage
subject(x)
subject(x, overwrite = FALSE) <- value
subject_create(
term,
subjectScheme = NA_character_,
schemeURI = NA_character_,
valueURI = NA_character_
)
Arguments
- x
An R object
- overwrite
Defaults to
FALSE
, in which case new subject(x) <- "Subject" calls are binding further Subjects to the already set Subject properties.- value
Subject terms, or a Subject object created by
subject_create
.- term
A term, or a character vector of multiple terms.
- subjectScheme
The scheme to which the term corresponds. If there are multiple terms, provide the subjectScheme(s) in the same order. Optional.
- schemeURI
The URI(s) of the subject identifier scheme. If there are multiple terms, provide the schemeURIs in the same order as the terms. Optional.
- valueURI
The URI of the subject term. If there are multiple terms, provide the valueURIs in the same order as the terms. Optional.
Details
In the Dublin Core elements, dct::subject is
defined Typically, the subject will be represented using keywords, key phrases, or classification codes. It is
recommended as a best practice to use a controlled vocabulary.
In DataCite, subjects are defined as key phrases from a controlled library.
Examples
x <- data.frame( geo = c("AL", "MK"),
value = c(1,2))
my_subject <- subject_create (
term = c("R (Computer program language)",
"Questionnaires--Computer programs"),
subjectScheme = rep("LC Subject Headings", 2),
schemeURI = rep("http://id.loc.gov/authorities/subjects",2),
valueURI = c("https://id.loc.gov/authorities/subjects/sh2002004407.html",
"http://id.worldcat.org/fast/1085693/")
)
subject(x) <- my_subject
subject(x)
#> term subjectScheme
#> 1 R (Computer program language) LC Subject Headings
#> 2 Questionnaires--Computer programs LC Subject Headings
#> schemeURI
#> 1 http://id.loc.gov/authorities/subjects
#> 2 http://id.loc.gov/authorities/subjects
#> valueURI
#> 1 https://id.loc.gov/authorities/subjects/sh2002004407.html
#> 2 http://id.worldcat.org/fast/1085693/
y <- data.frame()
subject(y) <- "R (Computer program language)"
subject(y) <- "Questionnaires--Computer programs"
subject(y)
#> term subjectScheme schemeURI valueURI
#> 1 R (Computer program language) <NA> <NA> <NA>
#> 2 Questionnaires--Computer programs <NA> <NA> <NA>