Re: [R] Polytopic Vector Analysis (PVA)

From: Kjetil Brinchmann Halvorsen <>
Date: Wed 14 Dec 2005 - 09:30:35 EST

Melanie Edwards wrote:
> I am curious whether anybody has or is developing this capability within
> R. I have not found any software yet that has this capability and I am
> not sure whether it is too new a method and nobody is actually using it,

googling around I found that this (PVA) is a variant of factor analysis restricted to find non-negative factors. It is not a new method, although maybe the name is. This has been/is used for instance in air quality monitoring to identify sources of pollution, and if you have some prior information about possible sources that maybe could be used to. I guess this could be called 'source unmixing' or something similar, which indicatyes a similarity with independent component analysis. Maybe enough to restrict optimization to non-negative values?"factor analysis") shows that factor analysis is multiply implemented for R, so maybe there is something, and if not, maybe simple to adapt.

Kjetil Halvorsen

> or if there are other means to get the same analysis that I do not know
> of. Any information regarding developments or use of this method would
> be helpful.
> Melanie Edwards
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> mailing list PLEASE do read the posting guide! Received on Wed Dec 14 10:32:39 2005

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