createLookup {eatGADS}

Extract values for recoding.

Description

Extract unique values from one or multiple variables of a GADSdat object for recoding (e.g. via an Excel spreadsheet).

Usage

createLookup(GADSdat, recodeVars, sort_by = NULL, addCols = c("value_new"))

Arguments

GADSdat

A GADSdat object.

recodeVars

Character vector of variable names which should be recoded.

sort_by

By which column (variable and/or value) should the long format data.frame be sorted? If NULL, no sorting is performed.

addCols

Character vector of additional column names for recoding purposes.

Details

If recoding of one or multiple variables is more complex, a lookup table can be created for later application via applyLookup or applyLookup_expandVar. The function allows the extraction of the values of multiple variables and sorting of these unique values via variable and/or values. If addCols are specified the lookup table has to be formatted via collapseColumns, before it can be applied to recode data.

Value

Returns a data frame in long format with the following variables:

variable

Variables as specified in recodeVars

value

Unique values of the variables specified in recodeVars

value_new

This is the default for addCols. If different additional column names are supplied, this column is missing.

Examples

# create example GADS
dat <- data.frame(ID = 1:4, var1 = c(NA, "Eng", "Aus", "Aus2"),
                  var2 = c(NA, "French", "Ger", "Ita"),
                  stringsAsFactors = FALSE)
gads <- import_DF(dat)

# create Lookup table for recoding
lookup <- createLookup(gads, recodeVars = c("var1", "var2"), sort_by = c("value", "variable"))

# create Lookup table for recoding by multiple recoders
lookup2 <- createLookup(gads, recodeVars = c("var1", "var2"), sort_by = c("value", "variable"),
                        addCols = c("value_recoder1", "value_recoder2"))