[R-SIG-Finance] plotting vertical lines on months in xyplot

[Joshua Ulrich]

Hi Worik,

I hope this doesn't come across as picky, but I cannot restrain myself
from improving your simple example.

On Tue, Mar 15, 2011 at 9:47 PM, Worik <worik.stanton at gmail.com> wrote:
> I have a similar problem as Jeff had back in the day.  I want to put a
> vertical line on a plot
>
> There must be a way....
>
> Simple example:
>
> library(xts)
> v <- vector()
> v[1] <- 10
> for(i in 2:100){
>  v[i] <- v[i-1]+rnorm(1, 0, 0.01)
> }

Growing vectors like this is slow.  rnorm() is vectorized.  Take
advantage of that.
V <- cumsum(c(10,rnorm(99,0,0.01)))

> X <- xts(v, seq(as.Date("2009-01-01"), by=1, length.out=100))
> plot(X)
>
> ## Try to put a vertical line in....
> abline(v=X[50,])
> abline(v=50)
> abline(v=index(X)[50])
>
>
>
> --
> If we amplify everything, we hear nothing.
> --
>
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--
Joshua Ulrich  |  FOSS Trading: www.fosstrading.com