[R] Thinning Lattice Plot

[Deepayan Sarkar]

On Tue, Jul 31, 2012 at 2:43 AM, Elliot Joel Bernstein
<elliot.bernstein at fdopartners.com> wrote:
> Is there an easy way to "thin" a lattice plot? I often create plots from
> large data sets, and use the "pdf" command to save them to a file, but the
> resulting files can be huge, because every point in the underlying dataset
> is rendered in the plot, even though it isn't possible to see that much
> detail.
>
> For example:
>
> require(Hmisc)
> x <- rnorm(1e6)
>
> pdf("test.pdf")
> Ecdf(x)
> dev.off()

(This is not a lattice plot, BTW.)

> The resulting pdf files is 31MB.

Hmm, for me it's 192K. Perhaps you have not bothered to update R recently.

> Is there any easy way to get a smaller pdf
> file without having to manually prune the dataset?

In general, as David noted, you need to do some sort of data
summarization; great if tools are available to that, otherwise
yourself. In this case, for example, it seems reasonable to do

Ecdf(quantile(x, probs = ppoints(500, a=1)))

If you don't like to do this yourself, ecdfplot() in latticeExtra will allow

library(latticeExtra)
ecdfplot(x, f.value = ppoints(500, a=1))

-Deepayan