questionr (version 0.7.7)

freq.na: Generate frequency table of missing values.

Description

Generate a frequency table of missing values as raw counts and percentages.

Usage

freq.na(data, ...)

Value

The result is an object of class data.frame.

Arguments

data

either a vector or a data frame object

...

if x is a data frame, the names of the variables to examine or keywords to search for such variables. See lookfor for more details.

See Also

table, is.na

Examples

data(hdv2003)
## Examine a single vector.
freq.na(hdv2003$qualif)
## Examine a data frame.
freq.na(hdv2003)
## Examine several variables.
freq.na(hdv2003, "nivetud", "trav.satisf")
## To see only variables with the most number of missing values
head(freq.na(hdv2003))