This function merges two variables that represent split versions of the same question (e.g., Q1_1 asked to one group and Q1_2 to another) into a single combined variable.
The function fills in missing values from one variable with non-missing values from the other, preserving factor levels and SPSS-style attributes.
Usage
combine(data, var_1, var_2, new_name = NULL, new_label = NULL)
Arguments
- data
A data frame containing the variables to combine.
- var_1
First variable to merge.
- var_2
Second variable to merge.
- new_name
(Optional) Name for the new variable. If omitted, defaults to var_1_var_2_COMB.
- new_label
(Optional) SPSS-style variable label. If omitted, the label from var_1 is copied.
Value
A modified data frame with a new combined variable placed immediately after var_2.
Details
If both variables have valid values for the same row, var_1 takes precedence (a warning is issued).
Factor levels are inherited from var_1.
Existing variables with the same name are overwritten.
To apply this function across multiple pairs of split variables, you can map it using the code block below:
pairs <- list(
list("Q1_1", "Q1_2"),
list("Q2_1", "Q2_2")
)
dat <- reduce(
pairs,
function(d, vars) {
combine(d, !!sym(vars[[1]]), !!sym(vars[[2]]))
},
.init = dat
)
Examples
# Combine Q1_1 and Q2_2
data <- combine(data = survey_data, var_1 = Q1_1, var_2 = Q1_2)
#> Error: These packages are required but not installed: dplyr
