[R] Second y-axis --- alternative to par(new=

[Petr PIKAL]

Hi

Rainer M Krug <r.m.krug at gmail.com> napsal dne 07.10.2009 12:40:39:

> 

> On Wed, Oct 7, 2009 at 12:26 PM, Petr PIKAL <petr.pikal at precheza.cz> 
wrote:
> Hi
> 
> Rainer M Krug <r.m.krug at gmail.com> napsal dne 07.10.2009 12:09:21:
> 
> >
> 

<snip>

> In the meantime, what about
> 
> x <- rnorm(200)
> hist(x, col = "blue", freq = TRUE)
> ddd<-density(x)
> lines(ddd$x, ddd$y*100, col = "red", lwd = 2)
> 
> and then add suitable y axis.
> 
> axis(4, at=pretty(ddd$y*100), labels=pretty(ddd$y), col=2)
> 
> Yes - that definitely works.
> 
> I usually use the following approach: determine the xlims in advance, 
and then
> set them manually for each plot:
> 
> x <- rnorm(200)
> xlim <- trunc(range(x)) + c(-1, +1)
> 
> hist(x, col = "blue", freq = TRUE, xlim=xlim)

hhh <- hist(x, col = "blue", freq = TRUE)

gives you object from which you can extract limits for plotting maybe 
better then from original data and you do not need to call

> par(new=TRUE)

Regards
Petr

> plot(density(x), xlim=xlim, ann=FALSE, axes=FALSE)
> axis(4)
>  
> But it is sometimes tricky to get the xlims for the plot.
> 
> Regards
> Petr
>