In memisc: Tools for Management of Survey Data and the Presentation of Analysis Results

% \VignetteIndexEntry{Combinding Flattened Contingency Tables (and Other Tables)} % \VignetteEngine{knitr::rmarkdown} % \VignetteEncoding{UTF-8}

knitr::opts_chunk$set(comment=NA,
               fig.align="center",
               results="markup")

Combinding Flattened Contingency Tables (and Other Tables)

This vignette demonstrates how flattened contingency tables can be combined into more complex tables. For starters, we create a few contingendy tables.

tab.Class.Age <- xtabs(Freq~Class+Age,data=Titanic)
tab.Survived.Class.Age <- xtabs(Freq~Survived+Class+Age,data=Titanic)
tab.Survived.Class.Sex <- xtabs(Freq~Survived+Class+Sex,data=Titanic)
tab.Survived.Class <- xtabs(Freq~Survived+Class,data=Titanic)
tab.Survived.Sex <- xtabs(Freq~Survived+Sex,data=Titanic)
tab.Survived.Age <- xtabs(Freq~Survived+Age,data=Titanic)
tab.Survived <- xtabs(Freq~Survived,data=Titanic)

Then we load the memisc package:

library(memisc)

Next, we create a few flattened contingency tables:

(ftab.Survived.Age <- ftable(tab.Survived.Age))
(ftab.Survived.Sex <- ftable(tab.Survived.Sex))

Since these tables have the same row variables, we can combine them columnwise:

cbind(ftab.Survived.Age,
      ftab.Survived.Sex)

We can even add a simple table of counts:

cbind(ftab.Survived.Age,
      ftab.Survived.Sex,
      Total=tab.Survived)

Of course, it is not enough to see such tables on screen, we also may need them in a presentable format, such as LaTeX or HTML. For the latter format we again have format_html and show_html. To see how this works, we first look at the individual ftables:

show_html(ftab.Survived.Age)

show_html(ftab.Survived.Sex)

... and then at their combination

show_html(
  cbind(ftab.Survived.Age,
      ftab.Survived.Sex,
      Total=tab.Survived)
)

To make, in "knitr", the creation of HTML-versions automatic one can use the following little trick:

knit_print.ftable_matrix <-function(x,options,...)
  knitr::asis_output(
    format_html(x,
                digits=if(length(options$ftable.digits))
                          options$ftable.digits
                       else 0,
                ...))

Now we do not need to call show_html while using "knitr":

cbind(ftab.Survived.Age,
      ftab.Survived.Sex,
      Total=tab.Survived)

This can be undone by removing the method function of knit_print:

rm(knit_print.ftable_matrix)

For show_html and toLatex there are some variants in how the variable names are positioned, for example:

show_html(
  cbind(ftab.Survived.Age,
      ftab.Survived.Sex,
      Total=tab.Survived),
  varinfront=FALSE
)

show_html(
  cbind(ftab.Survived.Age,
      ftab.Survived.Sex,
      Total=tab.Survived),
  varontop=FALSE
)

Of course it is also possible to combine flat contingency tables rowwise:

ftab.Age.Survived <- ftable(tab.Survived.Age,col.vars=1)
ftab.Sex.Survived <- ftable(tab.Survived.Sex,col.vars=1)
ftab.Class.Survived <- ftable(tab.Survived.Class,col.vars=1)

rbind(
  ftab.Age.Survived,
  ftab.Sex.Survived,
  ftab.Class.Survived,
  Total=tab.Survived
)

show_html(
  rbind(
    ftab.Age.Survived,
    ftab.Sex.Survived,
    ftab.Class.Survived,
    Total=tab.Survived
  )
)

It is also possible to create the ftables from tables of percentages or generic tables (created with genTable) etc.

ptab.Survived.Age<-percentages(Survived~Age,data=Titanic)
ptab.Survived.Sex<-percentages(Survived~Sex,data=Titanic)
ptab.Survived.Class<-percentages(Survived~Class,data=Titanic)

fptab.Age.Survived <- ftable(ptab.Survived.Age,col.vars=1)
fptab.Sex.Survived <- ftable(ptab.Survived.Sex,col.vars=1)
fptab.Class.Survived <- ftable(ptab.Survived.Class,col.vars=1)

show_html(
  rbind(
    fptab.Age.Survived,
    fptab.Sex.Survived,
    fptab.Class.Survived
  ),
  digits=1
)

It is also possible to combine rbind and cbind:

tab.Age <- xtabs(Freq~Age,data=Titanic)
tab.Sex <- xtabs(Freq~Sex,data=Titanic)
tab.Class <- xtabs(Freq~Class,data=Titanic)


show_html(
  rbind(
    cbind(fptab.Age.Survived,Total=tab.Age),
    cbind(fptab.Sex.Survived,Total=tab.Sex),
    cbind(fptab.Class.Survived,Total=tab.Class)
  ),
  digits=c(1,0) # One digit after dot for percentages 
                # no digits for total counts.
)

The same construct as LaTeX code:

toLatex(
  rbind(
    cbind(fptab.Age.Survived,Total=tab.Age),
    cbind(fptab.Sex.Survived,Total=tab.Sex),
    cbind(fptab.Class.Survived,Total=tab.Class)
  ),
  digits=c(1,0) # One digit after dot for percentages 
                # no digits for total counts.
)

memisc documentation built on May 2, 2019, 5:45 p.m.