[R] dotchart for matrix data

[Ben Bolker]

David Winsemius <dwinsemius <at> comcast.net> writes:

> 
> 
> On Dec 18, 2010, at 7:01 AM, e-letter wrote:
> 
> > Readers,
> >
> > I am trying to use the function dotchart. The data is:
> >
> >> testdot
> >  category values1 values2 values3 values4
> > 1        a      10      27      56     709
> > 2        b       4      46      47     208
> > 3        c       5      17      18     109
> > 4        d       6      50      49     308
> >
> > The following error occurs
> >
> >> dotchart(testdot,groups=testdot[,2])
> > Error in dotchart(testdot, labels = testdot[, 1], groups = testdot[,  
> > 2]) :
> >        'x' must be a numeric vector or matrix
> >
> > According to my understanding (clearly wrong!) of the documentation
> > for dotchart (accessed from the manual in section 'graphics'), columns
> > of data can be selected by 'groups' for subsequent plotting.
> 

  Following up on David's response:


d <- read.table(textConnection("category values1 values2 values3 values4
1        a      10      27      56     709
2        b       4      46      47     208
3        c       5      17      18     109
4        d       6      50      49     308"),
                header=TRUE)

## Something like this is probably as close as you can get with
## stock 'dotchart' -- it does *not* (as far as I can tell) put
## different points on the same line, just groups lines

dotchart(as.matrix(d[,-1]),labels=as.character(d[,1]))
dotchart(as.matrix(d[,c("values1","values2")]),labels=as.character(d[,1]))

## reshaping data:
library(reshape)
mdot <- melt(d)

## using the lattice package

library(lattice)
dotplot(value~category,groups=variable,data=mdot)
dotplot(value~variable,groups=category,data=mdot,auto.key=TRUE,
        scales=list(y=list(log=10)))

## you could also use ggplot2 ...