R: One-way frequency table for multiple choices question

multi.table {questionr} | R Documentation

## One-way frequency table for multiple choices question

### Description

This function allows to generate a frequency table from a multiple choices question. The question's answers must be stored in a series of binary variables.

### Usage

    multi.table(df, true.codes = NULL, weights = NULL, digits = 1,
      freq = TRUE)

### Arguments

`df` | data frame with the binary variables
`true.codes` | optional list of values considered as 'true' for the tabulation
`weights` | optional weighting vector
`digits` | number of digits to keep in the output
`freq` | add a percentage column

### Details

The function is applied to a series of binary variables, each one corresponding to a choice of the question. For example, if the question is about seen movies among a movies list, each binary variable would correspond to a movie of the list and be true or false depending of the choice of the answer.

By default, only '1' and 'TRUE' as considered as 'true' values fro the binary variables, and counted in the frequency table. It is possible to specify other values to be counted with the `true.codes` argument. Note than '1' and 'TRUE' are always considered as true values even if `true.codes` is provided.

If `freq` is set to TRUE, a percentage column is added to the resulting table. This percentage is computed by dividing the number of TRUE answers for each value by the total number of (potentially weighted) observations. Thus, these percentages sum can be greater than 100.

### Value

Object of class table.

### See Also

`cross.multi.table`, `multi.split`, `table`

### Examples

    ## Sample data frame
    set.seed(1337)
    sex <- sample(c("Man","Woman"),100,replace=TRUE)
    jazz <- sample(c(0,1),100,replace=TRUE)
    rock <- sample(c(TRUE, FALSE),100,replace=TRUE)
    electronic <- sample(c("Y","N"),100,replace=TRUE)
    weights <- runif(100)*2
    df <- data.frame(sex,jazz,rock,electronic,weights)
    ## Frequency table on 'music' variables
    multi.table(df[,c("jazz", "rock","electronic")], true.codes=list("Y"))
    ## Weighted frequency table on 'music' variables
    multi.table(df[,c("jazz", "rock","electronic")], true.codes=list("Y"), weights=df$weights)
    ## No percentages
    multi.table(df[,c("jazz", "rock","electronic")], true.codes=list("Y"), freq=FALSE)

[Package questionr version 0.6.3 Index]