R help - Jan 2011 - Grouped bars in barplot

Dear all,
 
I am trying to make a barplot with clustered pairs of bars, using class=numeric
data and the following command:
 
barplot(c(bline_precip[10,9], bline_runoff[10,9], cccma_precip[10,9],
cccma_runoff[10,9], csiro_precip[10,9], csiro_runoff[10,9], ipsl_precip[10,9],
ipsl_runoff[10,9], mpi_precip[10,9], mpi_runoff[10,9], ncar_precip[10,9],
ncar_runoff[10,9], ukmo_precip[10,9], ukmo_runoff[10,9]), beside=TRUE,
space=c(0,2))
 
This results in all bars being packed tightly together, but with no gap between
each pair. I suspect the problem is something to do with the data not being a
matrix, but I've tried using as.matrix for each data element and this
doesn't seem to work. If any one has any suggestions I'd be very
grateful to hear them.
 
Also, I'm hoping to put a label beneath each pair of bars on the x-axis, in
the centre. At present I can only get labels to appear directly underneath a
single bar, as opposed to the centre of the pair of bars. Does anyone have any
suggestions for solving this?
 
Many thanks for any help offered.
 
Steve

Tena koe Steve

Convert your data into a matrix:

dataMat <- matrix(c(bline_precip[10,9], bline_runoff[10,9],
                    cccma_precip[10,9], cccma_runoff[10,9],
                    csiro_precip[10,9], csiro_runoff[10,9],
                    ipsl_precip[10,9], ipsl_runoff[10,9],
                    mpi_precip[10,9], mpi_runoff[10,9],
                    ncar_precip[10,9], ncar_runoff[10,9],
                    ukmo_precip[10,9], ukmo_runoff[10,9]), nrow=2)

Since I don't know the nature of your data I will use a simple example:

dataMat <- matrix(1:14, nrow=2)
barplot(dataMat, beside=TRUE, space=c(0,2))
tTicks <- barplot(dataMat, beside=TRUE, space=c(0,2))
tTicks <- tapply(tTicks, rep(1:7, each=2), mean)
axis(1, tTicks, letters[1:7])

Is that what you want?

HTH ....

Peter Alspach
> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of Steve Murray
> Sent: Thursday, 13 January 2011 12:14 p.m.
> To: r-help at r-project.org
> Subject: [R] Grouped bars in barplot
> 
> 
> Dear all,
> 
> I am trying to make a barplot with clustered pairs of bars, using
> class=numeric data and the following command:
> 
> barplot(c(bline_precip[10,9], bline_runoff[10,9], cccma_precip[10,9],
> cccma_runoff[10,9], csiro_precip[10,9], csiro_runoff[10,9],
> ipsl_precip[10,9], ipsl_runoff[10,9], mpi_precip[10,9],
> mpi_runoff[10,9], ncar_precip[10,9], ncar_runoff[10,9],
> ukmo_precip[10,9], ukmo_runoff[10,9]), beside=TRUE, space=c(0,2))
> 
> This results in all bars being packed tightly together, but with no gap
> between each pair. I suspect the problem is something to do with the
> data not being a matrix, but I've tried using as.matrix for each data
> element and this doesn't seem to work. If any one has any suggestions
> I'd be very grateful to hear them.
> 
> Also, I'm hoping to put a label beneath each pair of bars on the x-
> axis, in the centre. At present I can only get labels to appear
> directly underneath a single bar, as opposed to the centre of the pair
> of bars. Does anyone have any suggestions for solving this?
> 
> Many thanks for any help offered.
> 
> Steve
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-
> guide.html
> and provide commented, minimal, self-contained, reproducible code.
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