[R] list to Matrix - remove NAs von list.

[Petr PIKAL]

Hi

r-help-bounces at r-project.org napsal dne 02.11.2007 12:00:09:

> Thanks,
> 
> I have the case that there is a NA in the list. This should not be a 
column.
> But na.omit(l) does not work for lists. How to remove NAs from a list?
> 
> l <- list(c(1,2,3),NA,c(1,2,3))
> mat <- do.call(cbind, l)

If number of NA is not big you can use

 mat[,which(!is.na(colSums(mat)))]

to select non NA columns.

Regards
Petr

> 
> Best
> Markus
> 
> 
> Dimitris Rizopoulos schrieb:
> > you can use do.call(), e.g.,
> >
> > do.call(cbind, l)
> >
> >
> > I hope it helps.
> >
> > 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 Markus Schmidberger <schmidb at ibe.med.uni-muenchen.de>:
> >
> >> Hello,
> >>
> >> I have a list of vectors (all the same length). How to convert the 
list
> >> to a matrix? Each vector should be a column.
> >> I tried this:
> >>
> >> l <- list(c(1,2,3),c(1,2,3),c(1,2,3))
> >> mat <- matrix( unlist(l), nrow=length(l) )
> >>
> >> But I think this is not very efficient. Is there a better solution?
> >>
> >> Thanks
> >> Markus
> >>
> >> -- 
> >> Dipl.-Tech. Math. Markus Schmidberger
> >>
> >> Ludwig-Maximilians-Universität München
> >> IBE - Institut für medizinische Informationsverarbeitung,
> >> Biometrie und Epidemiologie
> >> Marchioninistr. 15, D-81377 Muenchen
> >> URL: http://ibe.web.med.uni-muenchen.de
> >> Mail: Markus.Schmidberger [at] ibe.med.uni-muenchen.de
> >>
> >> ______________________________________________
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> >> http://www.R-project.org/posting-guide.html
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> >>
> >>
> >
> >
> >
> > Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm
> >
> 
> 
> -- 
> Dipl.-Tech. Math. Markus Schmidberger
> 
> Ludwig-Maximilians-Universität München
> IBE - Institut für medizinische Informationsverarbeitung,
> Biometrie und Epidemiologie
> Marchioninistr. 15, D-81377 Muenchen
> URL: http://ibe.web.med.uni-muenchen.de 
> Mail: Markus.Schmidberger [at] ibe.med.uni-muenchen.de
> Tel: +49 (089) 7095 - 4599
> 
> ______________________________________________
> R-help at r-project.org 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.