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 or dataset::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 current Subject property instead of overwriting it. Defaults to FALSE.
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"