preparing data for barplot()

What is the best way to produce a barplot from my data?  I would like
the barplot to show each person with the values stacked
val1+val2+val3, so there is one bar for each person  When I use
barplot(data.matrix(realdata)), it shows one bar for each value
instead.

To post here, I created an artificical data set, but it works fine.

fakedata <- as.data.frame(list(LETTERS[1:3]))
colnames(fakedata) <- 'people'
fakedata['val1'] = abs(rnorm(3))
fakedata['val2'] = abs(rnorm(3))
fakedata['val3'] = abs(rnorm(3))
barplot(data.matrix(fakedata))

At a glance there is no substantial difference is between my fake data
and my real data.

realdata

  person val1 val2 val3
1      A  221   71  175
2      B  222   85  147

mydata

  people       val1     val2       val3
1      A 0.75526748 0.445386 0.09186245
2      B 0.06107566 2.008815 2.50269410
3      C 0.47171611 0.592037 0.57612168

However

data.matrix(realdata)

  person val1 val2 val3
1     NA  221   71  175
2     NA  222   85  147
Warning messages:
1: NAs introduced by coercion
2: NAs introduced by coercion

So then I converted 'person' from a list to factors, which removed the
coercision error, but barplot() still shows each bar as value instead
of a person.

My serialized() data subset is here (look at bottom half where there
are no line numbers)
http://pastebin.com/m6d1e1d79


Thanks in advance,
Andrew

Read what barplot does and look to your plot.

If you want each row to be plotted as stacked bar with names uder each bar
taken from peaople variable then you need to

transpose your matrix - barplot takes columns
plot without names - you do not want them really plotted
add names under each bar - that is what names.arg is for

barplot(t(data.matrix(fakedata[,-1])), names.arg=fakedata$people)

Regards
Petr

r-help-bounces at r-project.org napsal dne 03.03.2009 19:00:12:

What is the best way to produce a barplot from my data? ?I would like
the barplot to show each person with the values stacked
val1+val2+val3, so there is one bar for each person ?When I use
barplot(data.matrix(realdata)), it shows one bar for each value
instead.