multi.table: 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)

Value

Object of class table.

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.

Examples

Run this code

## 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)