Re: [R] classification tables

From: Gabor Grothendieck <ggrothendieck_at_gmail.com>
Date: Mon 07 Aug 2006 - 21:04:21 EST

Also check out CrossTable in the gmodels package.

Regarding your other question, assuming we have tab<-table(x,y) as in Philippe's post, the fraction of pairs in x and y that match can be calculated via any of these:

  sum(x==y) / length(x)

  sum(diag(tab)) / sum(tab)

  library(e1071)
  classAgreement(tab) # tab from above

  sum(diag(prop.table(tab)))

On 8/7/06, Philippe Grosjean <phgrosjean@sciviews.org> wrote:
>
> > x <- c(1,2,3,4,2,3,3,1,2,3)
> > y <- c(2,1,3,4,1,3,3,2,2,3)
> > table(x, y)
> y
> x 1 2 3 4
> 1 0 2 0 0
> 2 2 1 0 0
> 3 0 0 4 0
> 4 0 0 0 1
> > ?table
>
> Best,
>
> Philippe Grosjean
>
> ..............................................<}))><........
> ) ) ) ) )
> ( ( ( ( ( Prof. Philippe Grosjean
> ) ) ) ) )
> ( ( ( ( ( Numerical Ecology of Aquatic Systems
> ) ) ) ) ) Mons-Hainaut University, Belgium
> ( ( ( ( (
> ..............................................................
>
> Taka Matzmoto wrote:
> > Dear R-users
> >
> > I have two vectors. One vector includes true values and the other vector has
> > estimated values. Values are all integers from 1 to 4.
> >
> > For example,
> >
> > x <- c(1,2,3,4,2,3,3,1,2,3)
> > y <- c(2,1,3,4,1,3,3,2,2,3)
> >
> > I would like to a classfication table x by y. With the table, I would like
> > to calculate what percentage is correct classfication.
> >
> > Which R function do I need to use for creating a 4 * 4 classification table?
> >
> > Thank you.
> >
> > Taka,
> >
> > ______________________________________________
> > R-help@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.
> >
> >
>
> ______________________________________________
> R-help@stat.math.ethz.ch mailing list
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>



R-help@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. Received on Tue Aug 08 10:38:34 2006

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