comtradr (version 0.0.2)

commodity_lookup: UN Comtrade commodities lookup table query

Description

The Comtrade API requires that searches for specific commodities be done using commodity codes. This is a helper function for querying the commodity code lookup table that's created by function ct_commodities_table. It takes as input a vector of commodities or commodity codes. If input is a commodity, then output is all commodity codes and descriptions that are associated with the input value. If input is a commodity code, then output is the commodity description associated with that input code. For use with the UN Comtrade API, full API docs can be found at https://comtrade.un.org/data/doc/api/

Usage

commodity_lookup(values, lookuptable, return_code = FALSE,
  return_char = FALSE, verbose = TRUE)

Arguments

values

Commodity names or commodity codes, as a char or numeric vector.

lookuptable

Dataframe of commodity descriptions and codes (intended input is the dataframe created by function ct_commodities_table).

return_code

Logical, if set to FALSE, the function will return a set of commodity descriptions along with commodity codes (as a single string for each match found), if set to TRUE it will return only the commodity codes. Default value is FALSE.

return_char

Logical, if set to FALSE, the function will return the matches as a named list, if set to TRUE it will return them as a character vector. Default value is FALSE.

verbose

Logical, if set to TRUE, a warning message will print to console if any of the elements of input "values" returned no matches (message will indicate which elements returned no data). Default is TRUE.

Value

A list or character vector of commodity descriptions and/or commodity codes that are matches with the elements of "values".

Examples

# NOT RUN {
# Look up commodity descriptions related to "halibut"
commoditydf <- ct_commodities_table("HS")
commodity_lookup("halibut",
                 commoditydf,
                 return_code = FALSE,
                 return_char = FALSE,
                 verbose = TRUE)
$halibut
[1] "030221 - Fish; halibut (reinhardtius hippoglossoides, hippoglossus
 hippoglossus, hippoglossus stenolepis), fresh or chilled (excluding
 fillets, livers, roes and other fish meat of heading no. 0304)"
[2] "030331 - Fish; halibut (reinhardtius hippoglossoides, hippoglossus
 hippoglossus, hippoglossus stenolepis), frozen (excluding fillets, livers,
 roes and other fish meat of heading no. 0304)"

# Look up commodity codes related to "shrimp".
comtradr::commodity_lookup("shrimp",
                           commoditydf,
                           return_code = TRUE,
                           return_char = FALSE,
                           verbose = TRUE)
$shrimp
[1] "030613" "030616" "030617" "030623" "030626" "030627" "030635" "030636"
 "030695" "160520" "160521" "160529" "160540"
# }