R help - Dec 2009 - histbackback function

Hi,
I'm trying to recreate a sensitivity-specificity graph using the
histbackback function.  The only problem is that these graphs are typically
drawn with vertical rather than horizontal bar plots (and the histbackback
function only seems to work with horiz=TRUE argument, using
"horiz=FALSE"
doesn't work).  Does anyone know if:
1) there's a different graphing function that would accomplish this graph?
2) if there isn't, is there a way to rotate the graph 90 degrees clockwise?
3) with the histbackback function, is there a way to display percent instead
of proportion on the x-axis?
4) with the histbackback function, is there a way to set the width of the
bins (ie I want bars in increments of 10 or 20 instead of 50 ,
"bin=10"
didn't work)
5) with the histbackback function, is there a way to display the y-axis
values where the two histograms are back to back, rather than on the y-axis?

Below, I've pasted the graph that I'm trying to recreate, as well as the
code and graph from my current (unsuccessful) attempt.  

options(digits=1)
require(Hmisc)
out <- histbackback(split(data8$TB144, data8$PRES), probability=TRUE,
main="Back to Back Histogram", ylab="TB144 1min rates")
barplot(-out$left, col="ivory2", horiz=TRUE, space=0, add=TRUE,
axes=FALSE)
barplot(out$right, col="ivory4", horiz=TRUE, space=0, add=TRUE,
axes=FALSE)
grid(nx=NULL, ny = NULL, col = "lightgray", lty = "dotted",
lwd par("lwd"), equilogs = TRUE)

http://n4.nabble.com/file/n954888/sens-spec%2Bgraph.jpg 

http://n4.nabble.com/file/n954888/back-to-back%2Bhistogram%2B2.jpg 

Thanks!
Katie
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>
> Hi,
> I'm trying to recreate a sensitivity-specificity graph using the
> histbackback function.  The only problem is that these graphs are typically
> drawn with vertical rather than horizontal bar plots (and the histbackback
> function only seems to work with horiz=TRUE argument, using
"horiz=FALSE"
> doesn't work).  Does anyone know if:
> 1) there's a different graphing function that would accomplish this
graph?
> 2) if there isn't, is there a way to rotate the graph 90 degrees
clockwise?
> 3) with the histbackback function, is there a way to display percent
instead
> of proportion on the x-axis?
> 4) with the histbackback function, is there a way to set the width of the
> bins (ie I want bars in increments of 10 or 20 instead of 50 ,
"bin=10"
> didn't work)
> 5) with the histbackback function, is there a way to display the y-axis
> values where the two histograms are back to back, rather than on the
y-axis?
>
> Below, I've pasted the graph that I'm trying to recreate, as well
as the
> code and graph from my current (unsuccessful) attempt.
>
> options(digits=1)
> require(Hmisc)
> out<- histbackback(split(data8$TB144, data8$PRES), probability=TRUE,
> main="Back to Back Histogram", ylab="TB144 1min rates")
> barplot(-out$left, col="ivory2", horiz=TRUE, space=0, add=TRUE,
axes=FALSE)
> barplot(out$right, col="ivory4", horiz=TRUE, space=0, add=TRUE,
axes=FALSE)
> grid(nx=NULL, ny = NULL, col = "lightgray", lty =
"dotted", lwd > par("lwd"), equilogs = TRUE)
>
> http://n4.nabble.com/file/n954888/sens-spec%2Bgraph.jpg
>
> http://n4.nabble.com/file/n954888/back-to-back%2Bhistogram%2B2.jpg
>
>
>    
Hi Katie,
You can get most of what you want with "barplot":

sens<-c(2,4,6,5,7,6,9,10,12)
spec<-c(7,4,5,3,1,0,0,1,0)
xpos<-barplot(sens,ylim=c(-15,15),col=NA,axes=FALSE)
barplot(-spec,add=TRUE)
axis(2,at=c(-10,0,10),labels=c(-10,0,10))
par(xpd=TRUE)
text(xpos,sens+1,sens)
text(xpos,-(spec+1),spec)
par(xpd=FALSE)

except that the "axes" argument doesn't seem to work. I can't
read your
example, but this should give you the idea.

Jim