R: Recode values of a variable to missing values, using exact or...

recode.na {questionr} | R Documentation

## Recode values of a variable to missing values, using exact or regular expression matching.

### Description

This function recodes selected values of a quantitative or qualitative variable by matching its levels to exact or regular expression matches.

### Usage

    recode.na(x, ..., verbose = FALSE, regex = TRUE, as.numeric = FALSE)

### Arguments

`x` | variable to recode. The variable is coerced to a factor if necessary.
`...` | levels to recode as missing in the variable. The values are coerced to character strings, meaning that you can pass numeric values to the function.
`verbose` | print a table of missing levels before recoding them as missing. Defaults to `FALSE`.
`regex` | use regular expressions to match values that include the "*" or "|" wildcards. Defaults to `TRUE`.
`as.numeric` | coerce the recoded variable to `numeric`. The function recommends the option when the recode returns only numeric values. Defaults to FALSE.

### Value

The result is a factor with properly encoded missing values. If the recoded variable contains only numeric values, it is converted to an object of class `numeric`.

### Author(s)

François Briatte <f.briatte@gmail.com>

### See Also

`regex`

### Examples

    data(hdv2003)
    ## With exact string matches.
    hdv2003$nivetud = recode.na(hdv2003$nivetud, "Inconnu")
    ## With regular expressions.
    hdv2003$relig = recode.na(hdv2003$relig, "[A|a]ppartenance", "Rejet|NSP")
    ## Showing missing values.
    hdv2003$clso = recode.na(hdv2003$clso, "Ne sait pas", verbose = TRUE)
    ## Test results with freq.
    freq(recode.na(hdv2003$trav.satisf, "Equilibre"))
    ## Truncate a count variable (recommends numeric conversion).
    freq(recode.na(hdv2003$freres.soeurs, 5:22))

[Package questionr version 0.6.3 Index]