[R] Back-to-back graph with lattice package

[Erik Svensson]

Hi,
Thank you for your reply.
I have looked into the epicalc package already and it will not help me
this time.
I realize that I wasn't clear enough. In my example I want to relate
all my data to Country, i.e. the distribution of Hair,  Eye color, Sex
(they are dichotomous in my example) and Age should all be related to each of
the five countries.

Pyramid in epicalc can't be used for relating e.g.Hair with Country,
and I can't get the labels for countries. Furthermore, I want all the
data in the nice panels of lattice as one single plot, which will occupy
rather little space.

So, yes, I'm looking for a work-around.
When I make barcharts or dotplots from my categorical data, I first
need make a table. One work-around could be to  e.g. in the Sex-column
of the table multiply the values for male by '-1' to get negative
values, Then the bars or dots for male would go to the left and the
female bars go to the right. Unfortunately, I don't know how do these
calculations and if the plot looks good.

Erik

2009/10/30 David Winsemius <dwinsemius at comcast.net>:
>
> On Oct 30, 2009, at 9:11 AM, Erik Svensson wrote:
>
>> Hi,
>> I am an [R] and lattice beginner.
>> I an doing an epidemiological study and want to present my data in a
>> condensed and clear manner as possible.
>>
>> The example below is fake, but representative for the the data I want to
>> show.
>>
>> I have a data frame with different categorical data and one column of
>> numerical data:
>>
>> Country, Hair, Eyes, Sex, Age
>> sweden, blond, blue, male, 25
>> sweden, dark, brown, female, 30
>> denmark, dark, blue, male, 22
>> denmark, blond, blue, female 33
>> norway, dark, blue, female, 21
>> norway, blond, blue, male, 31
>> finland, dark, blond, male, 43
>> island, blond, blue, female, 40
>> ...and so on for 300 rows...
>>
>> Country <- as.factor(rep(c("Sweden", "Denmark", "Norway", "Finland",
>> "Iceland","Sweden", "Denmark", "Norway", "Finland","Sweden" ),50))
>> Hair <- as.factor(rep(c("blond",  "dark", "blond", "dark", "blond"),100))
>> Eyes <- as.factor(rep(c("blue",  "blue", "blue", "brown"),125))
>> Sex <- as.factor(rep(c("male",  "female", "female", "male"),125))
>> Age <- rep(c(1:20, 1:100, 76:80),4)
>>
>>
>> Country has 5 levels, Age has many.
>> Hair, Eyes, and Sex have two levels each
>>
>> I want to do one lattice graph with 5 columns of panels with these
>> descriptive data.
>> I would prefer to use the lattice barchart or the corresponding
>> dotplot with lines (except for the Age panel)
>>
>> The  Age panel and probably the Country panel I think I can solve myself:
>>        barchart(Country)  # This only gives one panel, though...
>>        densityplot(~ Age|Country,  layout=c(1,5), xlim=c(0,100),scales =
>> list(y=list (relation="free")))
>>
>> But, for the dichotomous variables Hair, Eyes, and Sex columns I would
>> like to have a bihistogram aka back-to-back aka age-sex-pyramid
>> solution.
>> I want all bars to be horizontal, the names of the countries to the
>> left on the y-axis.
>> I would also like to sort the country names according to a list of their
>> names.
>>
>> For the back-to-back graph  I have only managed to get two panels per
>> column instead of one:
>>        barchart(table(Country, Hair),groups=FALSE)
>
> My suggestion would be to look for a worked solution.
>
> library(sos)
> ???pyramid
>
> The two I found upon taking my own advice are pyramid in epicalc and
> pyramid.plot in plotrix. Experimenting shows that the epicalc pyramid
> solution is more flexible and requires less pre-processing of the data.
>
> library(epicalc)
> data(Oswego)
> use(Oswego)
> pyramid(age, sex)
>
> # ... and on your data:
> pyramid(Age, Hair)    # ... seems to deliver the requested plot.
>
>
>>
>> How can I do all this? Is it possible at all?
>
> library(fortunes)
> fortune("Only how")
>
>>
>> Erik Svensson
>
> --
> David Winsemius, MD
> Heritage Laboratories
> West Hartford, CT
>
>