[R] Problem with memory footprint of qq plot generated with lattice
dhinds@sonic.net
dhinds at sonic.net
Thu Sep 29 01:53:02 CEST 2005
nwew <W.E.Wolski at newcastle.ac.uk> wrote:
> Dear R helpers,
> I generate a qq plot using the following function call.
...
> dim(xx)
> [1] 680237 2
How about doing something like this:
fn <- function(n,cut=0.001,m=1000)
{
p <- ppoints(n)
p <- p[pmin(p, 1-p) < cut]
q <- pt(seq(qt(cut,df=19),qt(1-cut,df=19),length=m),df=19)
sort(c(p,q))
}
then adding 'f.value=fn' to your qqmath arguments? This essentially
says, plot the individual data points in the extreme tails of the
distribution (p < 0.001 or p > 0.999), and evaluate the distribution
at a sparse set of points in between, where the density means you
can't discern the individual values anyway.
-- Dave
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