Recode one or more variables — recodes • qacBase

recodes recodes the values of one or more variables in a data frame

recodes(data, vars, from, to)

Arguments

data: a data frame.
vars: character vector of variable names.
from: a vector of values or conditions (see Details).
to: a vector of replacement values.

Value

a data frame

Details

For each variable in the vars parameter, values are checked against the list of values in the from vector. If a value matches, it is replaced with the corresponding entry in the to vector.
Once a given observation's value matches a from value, it is recoded. That particular observation will not be recoded again by that recodes() statement (i.e., no chaining).
One or more values in the from vector can be an expression, using the dollar sign ($) to represent the variable being recoded. If the expression evaluates to TRUE, the corresponding to value is returned.
If the number of values in the to vector is less than the from vector, the values are recycled. This lets you convert several values to a single outcome value (e.g., NA).
If the to values are numeric, the resulting recoded variable will be numeric. If the variable being recoded is a factor and the to values are character values, the resulting variable will remain a factor. If the variable being recoded is a character variable and the to values are character values, the resulting variable will remain a character variable.

Note

See the vignette for detailed examples.

Examples

df <- data.frame(x = c(1, 5, 7, 3, 0),
                 y = c(9, 0, 5, 9, 2),
                 z = c(1, 1, 2, 2, 1)
                 )
df <- recodes(df, 
              vars = c("x", "y"), 
              from = 0, to = NA)
df <- recodes(df, 
              vars = "z", 
              from = c(1, 2), to = c("pass", "fail"))