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Get subsets of indicator data

Source: R/check_and_get.R
get_data.coin.Rd

A flexible function for retrieving data from a coin, from a specified data set. Subsets of data can be returned based on selection of columns, using the iCodes and Level arguments, and by filtering rowwise using the uCodes and use_group arguments. The also_get argument also allows unit metadata columns to be attached, such as names, groups, and denominators.

Usage

# S3 method for coin
get_data(
  x,
  dset,
  iCodes = NULL,
  Level = NULL,
  uCodes = NULL,
  use_group = NULL,
  also_get = NULL,
  ...
)

Arguments

x

A coin class object

dset

The name of the data set to apply the function to, which should be accessible in .$Data.

iCodes

Optional indicator codes to retrieve. If NULL (default), returns all iCodes found in the selected data set. Can also refer to indicator groups. See details.

Level

Optionally, the level in the hierarchy to extract data from. See details.

uCodes

Optional unit codes to filter rows of the resulting data set. Can also be used in conjunction with groups. See details.

use_group

Optional group to filter rows of the data set. Specified as list(Group_Var = Group), where Group_Var is a Group_ column that must be present in the selected data set, and Group is a specified group inside that grouping variable. This filters the selected data to only include rows from the specified group. Can also be used in conjunction with uCodes -- see details.

also_get

A character vector specifying any columns to attach to the data set that are not indicators or aggregates. These will be e.g. uName, groups, denominators or columns labelled as "Other" in iMeta. These columns are stored in .$Meta$Unit to avoid repetition. Set also_get = "all" to attach all columns, or set also_get = "none" to return only numeric columns, i.e. no uCode column.

...

arguments passed to or from other methods.

Value

A data frame of indicator data according to specifications.

Details

The iCodes argument can be used to directly select named indicators, i.e. setting iCodes = c("a", "b") will select indicators "a" and "b", attaching any extra columns specified by also_get. However, using this in conjunction with the Level argument returns named groups of indicators. For example, setting iCodes = "Group1" (for e.g. an aggregation group in Level 2) and Level = 1 will return all indicators in Level 1, belonging to "Group1".

Rows can also be subsetted. The uCodes argument can be used to select specified units in the same way as iCodes. Additionally, the use_group argument filters to specified groups. If uCodes is specified, and use_group refers to a named group column, then it will return all units in the groups that the uCodes belong to. This is useful for putting a unit into context with its peers based on some grouping variable.

Note that if you want to retrieve a whole data set (with no column/row subsetting), use the get_dset() function which should be slightly faster.

Examples

# build full example coin
coin <- build_example_coin(up_to = "new_coin", quietly = TRUE)

# get all indicators in "Political group
x <- get_data(coin, dset = "Raw", iCodes = "Political", Level = 1)
head(x, 5)
#>    uCode Embs IGOs   UNVote
#> 31   AUS   82  196 38.46245
#> 1    AUT   88  227 42.63920
#> 2    BEL   84  248 43.00308
#> 32   BGD   52  145 38.60601
#> 3    BGR   67  209 42.95986

# see vignette("data_selection") for more examples