[R] Improving effeciency - better table()?
cullens at tcd.ie
Tue Jul 6 18:11:38 CEST 2004
On Tue, 6 Jul 2004 09:02:26 -0400, Liaw, Andy <andy_liaw at merck.com> wrote:
> Since you didn't provide an example of what z.trun and breaks may look
> like, most people can only guess. Before asking how code can be made
> efficient, it might be more helpful to find out where in the code is
> time. Try:
> obs <- table(cut2(z.trun, cuts=breaks))
Thanks, Andy. That helped to clear up some of my confusion. I have now
eliminated the call to cut2 and table and replaced that with hist, as
suggested by Roger Peng.
However I had changed much more code than I had initially realised and it
seems that the other code is having a larger effect. I've attached the
output of an experiment (a power test with 1000 iterations - code
included) and it seems that the problem is getting the expected number of
observations in each cell. I have to integrate the density that I am
working with in order to do this as it isn't standard.
I know that, firstly, using a for() loop is bad but the problem didn't
lend itself to vectorisation (I thought). Any help would be appreciated.
Dept. Of Economics
Trinity College Dublin
Email cullens at tcd.ie
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