[R-SIG-Finance] abline for quantmod charts

[Hae Kyung Im]

Hi,

I was trying to add vertical lines to a quantmod plot using

abline( v = somdatetime ) like in the following example

> getSymbols("YHOO")
[1] "YHOO"
> chartSeries(YHOO)
> abline( v=as.POSIXct("2008-04-01","%Y-%m-%d") )

But nothing shows up on the chart.

Any ideas on how to do this?

Thanks
Haky