Get a piece of a label — get

This is a wrapper function for get_pref_suff(), get_nouns(), and get_objects(). It returns a piece of a row or column label.

Usage

get_piece(
  labels,
  piece = "all",
  inf_notation = TRUE,
  notation = RCLabels::notations_list,
  choose_most_specific = FALSE,
  prepositions = RCLabels::prepositions_list
)

Arguments

labels: The row and column labels from which prepositional phrases are to be extracted.
piece: The name of the item to return.
inf_notation: A boolean that tells whether to infer notation for x. Default is TRUE. See infer_notation() for details.
notation: The notation type to be used when extracting prepositions. Default is RCLabels::notations_list, meaning that the notation is inferred using infer_notation().
choose_most_specific: A boolean that tells whether to choose the most specific notation from notation when inferring notation. Default is FALSE so that a less specific notation can be inferred. In combination with RCLabels::notations_list, the default value of FALSE means that RCLabels::bracket_notation will be selected instead of anything more specific, such as RCLabels::from_notation.
prepositions: A vector of strings to be treated as prepositions. Note that a space is appended to each word internally, so, e.g., "to" becomes "to ". Default is RCLabels::prepositions_list.

Value

A piece of labels.

Details

piece is typically one of

"all" (which returns labels directly),
"pref" (for the prefixes),
"suff" (for the suffixes),
"noun" (returns the noun),
"pps" (prepositional phrases, returns prepositional phrases in full),
"prepositions" (returns a list of prepositions),
"objects" (returns a list of objects with prepositions as names), or
a preposition in prepositions (as a string), which will return the object of that preposition named by the preposition itself.

piece must be a character vector of length 1. If a piece is missing in a label, "" (empty string) is returned.

If specifying more than one notation, be sure the notations are in a list. notation = c(RCLabels::bracket_notation, RCLabels::arrow_notation) is unlikely to produce the desired result, because the notations are concatenated together to form a long string vector. Rather say notation = list(RCLabels::bracket_notation, RCLabels::arrow_notation).

Examples

labs <- c("a [from b in c]", "d [of e in f]", "Export [of Coal from USA to MEX]")
get_piece(labs, "pref")
#>     pref     pref     pref 
#>      "a"      "d" "Export" 
get_piece(labs, "suff")
#>                      suff                      suff                      suff 
#>             "from b in c"               "of e in f" "of Coal from USA to MEX" 
get_piece(labs, piece = "noun")
#>     noun     noun     noun 
#>      "a"      "d" "Export" 
get_piece(labs, piece = "pps")
#>                       pps                       pps                       pps 
#>             "from b in c"               "of e in f" "of Coal from USA to MEX" 
get_piece(labs, piece = "prepositions")
#> $prepositions
#> [1] "from" "in"  
#> 
#> $prepositions
#> [1] "of" "in"
#> 
#> $prepositions
#> [1] "of"   "from" "to"  
#> 
get_piece(labs, piece = "objects")
#> $objects
#> from   in 
#>  "b"  "c" 
#> 
#> $objects
#>  of  in 
#> "e" "f" 
#> 
#> $objects
#>     of   from     to 
#> "Coal"  "USA"  "MEX" 
#> 
get_piece(labs, piece = "from")
#> [[1]]
#> from 
#>  "b" 
#> 
#> [[2]]
#> from 
#>   "" 
#> 
#> [[3]]
#>  from 
#> "USA" 
#> 
get_piece(labs, piece = "in")
#> [[1]]
#>  in 
#> "c" 
#> 
#> [[2]]
#>  in 
#> "f" 
#> 
#> [[3]]
#> in 
#> "" 
#> 
get_piece(labs, piece = "of")
#> [[1]]
#> of 
#> "" 
#> 
#> [[2]]
#>  of 
#> "e" 
#> 
#> [[3]]
#>     of 
#> "Coal" 
#> 
get_piece(labs, piece = "to")
#> [[1]]
#> to 
#> "" 
#> 
#> [[2]]
#> to 
#> "" 
#> 
#> [[3]]
#>    to 
#> "MEX" 
#>