[R] extract certain values from a ts

Gabor Grothendieck ggrothendieck at gmail.com
Tue Oct 24 21:26:33 CEST 2006


There was still a typo in this so here it is again:

# Consider the builtin in nhtemp "ts" series
# Then the runs below above and below the mean are
r <- rle(as.vector(nhtemp > mean(nhtemp)))
r

# with the first and last indexes of each
# runs being given by:

idx.last <- cumsum(r$lengths)
idx.first <- idx.last - r$lengths + 1

# and the first and last times of each run being

tt <- time(nhtemp)
cbind(tt[idx.first], tt[idx.last])


On 10/24/06, Gabor Grothendieck <ggrothendieck at gmail.com> wrote:
> On 10/24/06, Gabor Grothendieck <ggrothendieck at gmail.com> wrote:
> > # Consider the builtin in nhtemp "ts" series
> > # Then the runs below above and below the mean are
> > r <- rle(as.vector(nmtemp > mean(nhtemp)))
> > r
> >
> > # with the first and last indexes of each
> > # runs being given by:
> >
> > idx.last <- cumsum(r$lengths)
> > idx.first <- idx.last - r$lengths + 1
> >
> > # and the first and last times of each run being
> >
> The next statement was supposed to be
>
> tt <- time(nhtemp).
>
> I had started with Nile but then switched to nhtemp since it
> gave too much output for an example.
>
> > tt <- time(Nile)
> > cbind(tt[idx.first], tt[idx.last])
> >
> >
> > On 10/24/06, antonio rodriguez <antonio.raju at gmail.com> wrote:
> > > Hi,
> > >
> > > Having several daily wind speed time series I want to extract those
> > > consecutive days over and below certain values (i.e. 5 < x <8) Don't
> > > know which funtion to use (aggregate, lapply?) and how to do it.
> > >
> > > Thanks in advance
> > >
> > > Antonio
> > >
> > > ______________________________________________
> > > R-help at stat.math.ethz.ch mailing list
> > > https://stat.ethz.ch/mailman/listinfo/r-help
> > > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> > > and provide commented, minimal, self-contained, reproducible code.
> > >
> >
>



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