Create/add/retrieve a subject
Usage
subject(x)
subject_create(
term,
schemeURI = NULL,
valueURI = NULL,
prefix = NULL,
subjectScheme = NULL,
classificationCode = NULL
)
subject(x, overwrite = FALSE) <- value
is.subject(x)
Arguments
- x
A dataset object created with
dataset::dataset_df
ordataset::as_dataset_df
.- term
A subject term, for example,
"Data sets"
.- schemeURI
The URI of the subject identifier scheme, for example
"http://id.loc.gov/authorities/subjects"
- valueURI
The URI of the subject term.
"https://id.loc.gov/authorities/subjects/sh2018002256"
- prefix
An abbreviated prefix of a scheme URI, for example,
"lcch:"
representing"http://id.loc.gov/authorities/subjects"
. Widely used namespaces (schemes) have conventional abbreviations.- subjectScheme
The name of the subject scheme or classification code or authority if one is used. It is a namespace.
- classificationCode
The classificationCode subproperty may be used for subject schemes, like ANZSRC, which do not have valueURIs for each subject term.
- overwrite
If the attributes should be overwritten. In case it is set to
FALSE
, it gives a message with the currentSubject
property instead of overwriting it. Defaults toFALSE
.- value
A subject field created by
subject
.
Value
The Subject field of the dataset's attributes.
A named list with the subject term, the subject scheme, URIs and prefix.
Examples
subject(iris_dataset,
overwrite = TRUE) <- subject_create(
term = "Irises (plants)",
schemeURI = "http://id.loc.gov/authorities/subjects",
valueURI = "https://id.loc.gov/authorities/subjects/sh85068079",
subjectScheme = "LCCH",
prefix = "lcch:")
subject(iris_dataset)
#> $term
#> [1] "Irises (plants)"
#>
#> $subjectScheme
#> [1] "LCCH"
#>
#> $schemeURI
#> [1] "http://id.loc.gov/authorities/subjects"
#>
#> $valueURI
#> [1] "https://id.loc.gov/authorities/subjects/sh85068079"
#>
#> $classificationCode
#> NULL
#>
#> $prefix
#> [1] "lcch:"
#>
#> attr(,"class")
#> [1] "subject" "function"