# percentages: Easy Creation of Tables of Percentages In memisc: Management of Survey Data and Presentation of Analysis Results

 percentages R Documentation

## Easy Creation of Tables of Percentages

### Description

The generic function `percentages` and its methods create one- or multidimensional tables of percentages. As such, the function `percentages` can be viewed as a convenience interface to `prop.table`. However, it also allows to obtain standard errors and confidence intervals.

### Usage

``````percentages(obj, ...)
## S3 method for class 'table'
percentages(obj,
by=NULL, which=NULL, se=FALSE, ci=FALSE, ci.level=.95, ...)
## S3 method for class 'formula'
percentages(obj,
data=parent.frame(), weights=NULL, ...)
## Default S3 method:
percentages(obj,
weights=NULL, ...)
## S3 method for class 'data.frame'
percentages(obj,
weights=NULL, ...)
## S3 method for class 'list'
percentages(obj,
weights=NULL, ...)
## S3 method for class 'percentage.table'
as.data.frame(x, ...)
## S3 method for class 'xpercentage.table'
as.data.frame(x, ...)
``````

### Arguments

 `obj` an object; a contingency table or a formula. If it is a formula, its left-hand side determines the factor or combination of factors for which percentages are computed while its right-hand side determines the factor or combination of factors that define the groups within which percentages are computed. `by` a character vector with the names of the factor variables that define the groups within which percentages are computed. Percentages sum to 100 within combination of levels of these factors. `which` a character vector with the names of the factor variables for which percentages are computed. `se` a logical value; determines whether standard errors are computed. `ci` a logical value; determines whether confidence intervals are computed. Note that the confidence intervals are for infinite (or very large) populations. `ci.level` a numerical value, the required confidence level of the confidence intervals. `data` a contingency table (an object that inherits from "table") or a data frame or an object coercable into a data frame. `weights` an optional vector of weights. Should be NULL or a numeric vector. `...` Further arguments passed on to the "table" method of `percentages` or ignored in case of a call to `as.data.frame`. `x` an object coerced into a data frame.

### Value

An array that inherits classes "percentage.table" and "table". If `percentages` was called with `se=TRUE` or `ci=TRUE` then the result additionally inherits class "xpercentage.table".

### Examples

``````percentages(UCBAdmissions)

# Three equivalent ways to create the same table of conditional
# percentages
# Percentage table as data frame

# Standard errors and confidence intervals

# An extended table of percentages as data frame
as.data.frame(p)

# A table of percentages of a factor
percentages(iris\$Species)