[R-sig-Geo] eculidean threshold for clustering

[jgarcia at ija.csic.es]

Thank you, Marcelino, Roger and Alexander,
I didn't know any of these.
Cheers,
Javier
...

> This seems a single linkage clustering issue:
>
>  > grouping <- hclust(dist(data.frame(x,y)),"single")
>  > cutree(grouping, h=0.5)
> [1] 1 1 1 2 3 3 3
>
> Cheers,
>
> Marcelino
>
>
>
> At 13:04 26/10/2010, jgarcia at ija.csic.es wrote:
>>Dear all,
>>I am wondering if there is a direct function (I cannot find any) in R, to
>>obtain, a "factor" vector to identify which points could be grouped in a
>>set, using a specific threshold distance as clustering criterion.
>>
>>#e.g, with 7 points with coordinates:
>>
>>x <- c(1.01,0.95,1.05,1.03,3.03,2.99,3.04)
>>y <- c(3.01,3.02,3.04,5.23,2.01,2.02,1.98)
>>
>># and, let's say, distance threshold 0.5, the answer would be:
>>(1,1,1,2,3,3,3)
>>
>># where the threshold is the maximum distance between any two points for
>>each cluster
>>
>>A better approach would be that threshold could be specified as the
>>distance between any point in each cluster, and its corresponding center
>>of mass for that cluster, but I guess this would require some loops.
>> Isn't
>>it? S, I would be happy enough with the abovementioned approach.
>>
>>If there isn't a direct function, don't worry. I'll try to find a
>> solution
>>computing distances...
>>
>>Thanks,
>>Javier
>>---
>>
>>
>>
>>
>> > is it possible to load a complete Grass mapset into a raster stack or
>> > brick
>> > with a single command?
>> >
>> > --
>> > View this message in context:
>> >
>> http://r-sig-geo.2731867.n2.nabble.com/Grass-and-raster-package-tp5667199p5667199.html
>> > Sent from the R-sig-geo mailing list archive at Nabble.com.
>> >
>> > _______________________________________________
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>> >
>>
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> ____________________________________
>
> Marcelino de la Cruz Rot
> Depto. Biologia Vegetal
> EUIT Agricola
> Universidad Politecnica de Madrid
>
> tel: 34 + 913365435
> ____________________________________