R help - Aug 2006 - locating intervals (corrected version)

I have corrected a typo in my previous posting. In what follows the
line with the inequality is correct

Hi ,

I have two sorted vectors X and Xi, where the range of Xi lies within the
range of X.

For an element in Xi, I want to find the neigbouring data in X, e.g. find an
index ix
so that for element number k, then
X[ix[k]] < Xi[k] < X[ix[k] +1]  # also OK with "<=" on either
one, but not
both

This is easy to code by looping over the data in X,Xi, but I suspect there
may be a faster and more elegant way to do this in R.

In Python (Numeric) the same can be achieved with
ix=Numeric.searchsorted(X[1:-1],Xi),
which is quite compact.

So, does anyone know of a corresponding R  call that can achive the same?

Sincerely,
Halldór


-- 
Halldór Björnsson
Deildarstj. Ranns. & Þróun
Veðursvið Veðurstofu Íslands

Halldór Bjornsson
Weatherservice R & D
Icelandic Met. Office

	[[alternative HTML version deleted]]

?findInterval() could be of help in this case.

Best,
Dimitris


----
Dimitris Rizopoulos
Ph.D. Student
Biostatistical Centre
School of Public Health
Catholic University of Leuven

Address: Kapucijnenvoer 35, Leuven, Belgium
Tel: +32/(0)16/336899
Fax: +32/(0)16/337015
Web: http://med.kuleuven.be/biostat/
      http://www.student.kuleuven.be/~m0390867/dimitris.htm


Quoting halldor bjornsson <halldor.bjornsson at gmail.com>:
> I have corrected a typo in my previous posting. In what follows the
> line with the inequality is correct
>
> Hi ,
>
> I have two sorted vectors X and Xi, where the range of Xi lies within the
> range of X.
>
> For an element in Xi, I want to find the neigbouring data in X, e.g. find
an
> index ix
> so that for element number k, then
> X[ix[k]] < Xi[k] < X[ix[k] +1]  # also OK with "<=" on
either one, but not
> both
>
> This is easy to code by looping over the data in X,Xi, but I suspect there
> may be a faster and more elegant way to do this in R.
>
> In Python (Numeric) the same can be achieved with
> ix=Numeric.searchsorted(X[1:-1],Xi),
> which is quite compact.
>
> So, does anyone know of a corresponding R  call that can achive the same?
>
> Sincerely,
> Halld?r
>
>
> --
> Halld?r Bj?rnsson
> Deildarstj. Ranns. & ?r?un
> Ve?ursvi? Ve?urstofu ?slands
>
> Halld?r Bjornsson
> Weatherservice R & D
> Icelandic Met. Office
>
> 	[[alternative HTML version deleted]]
>
>


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