[R] 2 barplots in the same graph

[Romain Francois]

Le 24.02.2006 11:58, jia ding a écrit :
> Hi,
> Would you pls try  these?
>
>  x1<-c(1,2,10)
>  x2<-c(-3,5,-8)
>  barplot(x1,col="white",border="red",ylim=range(c(x1,x2)))
>  barplot(x2,col="white",border="green",ylim=range(c(x1,x2)),add=T)
>  axis(1, 0:3)
>  box()
>
ylim is not needed on the second call.

>
> Q1, on x-axis "1,2,3" is not shown at the middle position of the bars. 
> e.g for first bar, "1" is tend to right ; while third bar, "3" is tend 
> to left.

Use the outputs from barplot :

out <- barplot(x1,col="white",border="red",ylim=extendrange(c(x1,x2)))
out
axis(1, out[,1], sprintf('bar %d', 1:3))

> Q2, once >box(), then bars are cut again.

You can use extendrange instead of range, ie :

barplot(x1,col="white",border="red",ylim=extendrange(c(x1,x2)))

> Q3, when y-axis is "0", I want to draw a parallel line to  x-axis:
>       I tried >lines(c(0,5),c(0,0)) ; is there any other way to do it?

abline(h=0)

> Thanks.
>
> Nina
Also, try :
?barplot
http://addictedtor.free.fr/graphiques/search.php?q=barplot

Romain

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| Romain FRANCOIS - http://francoisromain.free.fr               |
| Doctorant INRIA Futurs / EDF                                  |
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