create_filter_table: Create a filter table

Description

Create filter table from the filters and date_filter strings parameters of the get_eurostat_data to be used in the filter_raw_data function for filtering by query or on the local computer.

Usage

create_filter_table(
  filters,
  date_filter = FALSE,
  dsd = NULL,
  exact_match = TRUE,
  verbose = FALSE,
  ...
)

Value

a data.table containing in each row a distinct filtering condition to be applied to a raw Eurostat datatable or generate specific query.

If date_filter=TRUE, the output data table contains two columns with the following names:

`sd`	Starting date to be included in the filtered dataset, where date is formatted yyyy[-mm][-dd]
`ed`	End date of the period to be included in the filtered dataset, where the date is formatted yyyy[-mm][-dd]

In case date_filter=FALSE, the output tables have the following four columns:

`pattern`	Containing those parts of the `filters` string where the string part (pattern) was found in the `dsd`
`concept`	The name of the concepts corresponding to the result in the code/name column where the pattern was found in the data structure definition
`code`	The list of codes where the pattern was found, or the code of a name (description of the code) where the pattern appears
`name`	The name (description of the code) which can be used as label for the code where the pattern was found, or the name (description of the code) of the code where the pattern appears

Arguments

filters: a string, a character or numeric vector or a named list containing words to filter by the different concepts, geographical location or time values. The words can be any word, Eurostat variable code, or value which are in the Data Structure Definition (DSD) and can be retrieved by the search_eurostat_dsd function. If a named list is used, then the name of the list elements should be the concepts from the DSD and the provided values will be used to filter the dataset for the given concept. The default is NULL, in this case no filter table is created. To filter by time see date_filter below. In case for filtering for time values, the date shall be defined as character string, and it should follow the format yyyy[-mm][-dd], where the month and the day part is optional.
date_filter: a logical value. If TRUE the filter table is genrated only for the time dimension. The default is FALSE, in this case a (dsd) should be provided which will be searched for the values given in the filters.
dsd: a table containing a DSD of an Eurostat dataset which can be retreived by the get_eurostat_dsd function.
exact_match: a logical value with the default value TRUE, if the strings provided in filters shall be matched exactly as it is or as a pattern in the DSD.
verbose: a logical value with default FALSE, so detailed messages (for debugging) will not printed. Can be set also with options(restatapi_verbose=TRUE)
...: further arguments to the for search_eurostat_dsd function, e.g.: ignore.case or name. The ignore.case has the default value FALSE, then the strings provided in filters are matched as is, otherwise the case of the letters is ignored. If the name=FALSE then the pattern(s) provided in the filters argument is only searched in the code column of the DSD, and the names of the codes will not be searched.

Details

It is a sub-function to use in the get_eurostat_data to generate url for the given filters and date_filter in that function. The output can be used also for filtering data on the local computer with the get_eurostat_raw and filter_raw_data function, if the direct response from REST API did not provide data because of too large data set.

Examples

Run this code

# \dontshow{
if (parallel::detectCores()<=2){
   options(restatapi_cores=1)
}else{
   options(restatapi_cores=2)
}    
cfg<-get("cfg",envir=restatapi::.restatapi_env) 
rav<-get("rav",envir=restatapi::.restatapi_env)
# }
# \donttest{
if (!(grepl("amzn|-aws|-azure ",Sys.info()['release']))) options(timeout=2)
dsd<-get_eurostat_dsd("avia_par_me") 
create_filter_table(c("KYIV","hu","Quarterly"),dsd=dsd,exact_match=FALSE,ignore.case=TRUE)
create_filter_table(c("KYIV","LHBP","Monthly"),dsd=dsd,exact_match=FALSE,name=FALSE)
create_filter_table(c("2017-03",
                      "2001-03:2005",
                      "<2000-07-01",
                      2012:2014,
                      "2018<",
                      20912,
                      "<3452<",
                      ":2018-04>",
                      "2<034v",
                      "2008:2013"),
                    date_filter=TRUE,
                    verbose=TRUE)
options(timeout=60)
# }