[R] Odp: Finding Coordinate of Max/Min Value in a Data Frame

[Petr PIKAL]

Hi

r-help-bounces at r-project.org napsal dne 11.06.2008 12:34:47:

> Hi,
> 
> Suppose I have the following data frame.
> 
> __BEGIN__
> 
> > library(MASS)
> > data(crabs)
> > crab.pca <- prcomp(crabs[,4:8],retx=TRUE)
> > crab.pca$rotation
>          PC1        PC2        PC3        PC4        PC5
> FL 0.2889810  0.3232500 -0.5071698  0.7342907  0.1248816
> RW 0.1972824  0.8647159  0.4141356 -0.1483092 -0.1408623
> CL 0.5993986 -0.1982263 -0.1753299 -0.1435941 -0.7416656
> CW 0.6616550 -0.2879790  0.4913755  0.1256282  0.4712202
> BD 0.2837317  0.1598447 -0.5468821 -0.6343657  0.4386868
> 
> __END__
> 
> Is there a way to identify the "coordinate" of a max/min value of all 
the
> points above.
> 

which(crab.pca$rotation==min(crab.pca$rotation), arr.ind=T)
which(crab.pca$rotation==max(crab.pca$rotation), arr.ind=T)

Regards
Petr

> For example the coord of maximum value is (RW,PC2) = 0.865,
> and coord of min value is (CW,PC2) = - 0.288.
> 
> -- 
> Gundala Viswanath
> 
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