Easy Creation of Tables of Percentages
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.
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, ...)
## S3 method for class 'percentage.table'
as.data.frame(x, ...)
## S3 method for class 'xpercentage.table'
as.data.frame(x, ...)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. |
x |
an object coerced into a data frame. |
... |
Further arguments, ignored. |
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".
# Two equivalent ways to create the same table
100*prop.table(UCBAdmissions)
percentages(UCBAdmissions)
# Three equivalent ways to create the same table
100*prop.table(UCBAdmissions,c(2,3))
(p0 <- percentages(UCBAdmissions,by=c("Gender","Dept")))
percentages(UCBAdmissions,which="Admit")
# Percentage table as data frame
as.data.frame(p0)
# Three equivalent ways to create the same table
100*prop.table(margin.table(UCBAdmissions,c(1,2)),2)
percentages(UCBAdmissions,which="Admit",by="Gender")
percentages(Admit~Gender,data=UCBAdmissions)
# Three equivalent ways to create the same table
100*prop.table(margin.table(UCBAdmissions,c(1,3)),2)
percentages(Admit~Dept,data=UCBAdmissions)
percentages(Admit~Dept,data=as.data.frame(UCBAdmissions),
weights=Freq)
# Standard errors and confidence intervals
percentages(Admit~Dept,data=UCBAdmissions,se=TRUE)
percentages(Admit~Dept,data=UCBAdmissions,ci=TRUE)
(p<- percentages(Admit~Dept,data=UCBAdmissions,ci=TRUE,se=TRUE))
# An extended table of percentages as data frame
as.data.frame(p)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.