ctab: Percentage tables

Description

Produces one-way, two-way or multi-way percentage tables

Usage

ctab(...,dec.places=NULL,digits=NULL,type=NULL,style=NULL,row.vars=NULL,col.vars=NULL,percentages=NULL,addmargins=NULL)
"print"(x, dec.places=x$dec.places, addmargins=x$addmargins, ...)
"summary"(object,...)

Arguments

...

either

one or more factors,
a class table
a class ftable table object,
or a class ctab table object

dec.places

number of decimal places (default 2)

digits

synonym for dec.places, for compatability with previous version

type

Row, column, total percentages or counts (type= n). Multiple values may be specified as a character vector. Partial matchin is used.

style

Applicable if more than one percentage type is specified. If style=long, percentages are printed underneath each other. If style=wide, the percentages are printed side by side

row.vars

Same as ftable: “a vector of integers giving the numbers of the variables, or a character vector giving the names of the variables to be used for the rows of the [] table”

col.vars

“a vector of integers giving the numbers of the variables, or a character vector giving the names of the variables to be used for the columns of the [] table”

percentages

If FALSE, proportions rather than percentages are printed

addmargins

Use addmargins=TRUE to add subtotals to the table

is a tables object created by ctab

object

is a tables object created by ctab

Value

table: A class(table) object containing the table counts. Used by summary.ctab and by ctab itself if a ctab object is used as input.
ctab: A class(ftable) object containing the percentage types specified. This is printed by print.ctab.
row.vars: The row.vars options as numeric vectors
col.vars: The col.vars options as numeric vectors
dec.places: The dec.places option
type: The type option
style: The style option
percentages: The percentages option
addmargins: The addmargins option

Details

Options have default NULL so attributes of a ctab object can be used as default. In other cases, the following options will be used if nothing has been specified:

ctab(\dots, dec.places=2, digits=dec.places, type=c("n", "row", "column", "total"),
style="long", row.vars=NULL, col.vars=NULL, percentages=TRUE, addmargins=FALSE)

ctab uses ftable and prop.table to produce one-way frequency tables, two-way crosstables, or multi-way percentage tables. More than one percentage type may be specified, in which case “percentage type” is an unnamed dimension of the table. row.vars and col.vars can be used to control the layout of multi-way tables using the facilities of ftable. Subtotals can be added by specifiying addmargins=TRUE.

CrossTable in the gmodels package also provides an easy method for producing percentage tables, but is restricted to two-way tables.

If ctab is specified with no further options and for more than one factor, the output is identical to that of ftable. If a single factor is specified, the default is to print the frequencies column-wise with the percentaqes next to them.

References

http://home.wanadoo.nl/john.hendrickx/statres/

Examples

Run this code

ftable(Titanic)
ctab(Titanic) # same output
ctab(Titanic,type="r")
ctab(Titanic,type=c("n","r"),addmargins=TRUE)
ctab(Titanic,type=c("n","c","t","r"),style="w")
mytab<-ftable(Titanic,row.vars=c(1,3),type="r")
mytab
ctab(mytab)
newtab<-ctab(mytab,type="r")
newtab
summary(newtab)

#second example using a data frame rather than table data
library(survival)
data(logan)
attach(logan)
class(logan) #"data.frame"
ctab(occupation)
ctab(occupation,addmargins=TRUE)
ctab(occupation,style="w",type="c")
ctab(occupation,style="l",type="n")
z<-ctab(occupation,addmargins=TRUE,style="l")
z
print(z,addmargins=FALSE,dec.places=5)
summary(z)

t<-ctab(focc,occupation,type=c("n","r","c"))
t
summary(t)

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