R help - Feb 2006 - Inf values in a matrix

Hello,

I have some Inf values in a matrix, but I don't want to replace them with
some value but rather remove the rows that contain the Inf values. Also I
would like to record the rows which were removed. Is there an easy way to
do this instead of writing loops over the matrix? Thanks.

Ita Cirovic Donev

try the following:

mat <- matrix(rnorm(40), 10, 4)
mat[sample(20, 5)] <- Inf
mat
##########
index <- rowSums(!is.finite(mat)) >= 1
mat. <- mat[!index, ]

which(index)
mat.


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://www.med.kuleuven.be/biostat/
     http://www.student.kuleuven.be/~m0390867/dimitris.htm


----- Original Message ----- 
From: <Ita.Cirovic-Donev at hypo-alpe-adria.com>
To: <r-help at stat.math.ethz.ch>
Sent: Tuesday, February 14, 2006 5:01 PM
Subject: [R] Inf values in a matrix

>
>
>
>
> Hello,
>
> I have some Inf values in a matrix, but I don't want to replace them 
> with
> some value but rather remove the rows that contain the Inf values. 
> Also I
> would like to record the rows which were removed. Is there an easy 
> way to
> do this instead of writing loops over the matrix? Thanks.
>
> Ita Cirovic Donev
>
> ______________________________________________
> R-help at 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
> 

Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm

Hi

see
?is.infinite
?which
something like

y <- x[-which(is.infinite(x), arr.ind=T)[,1],]
y.removed <-x[which(is.infinite(x), arr.ind=T)[,1],]
shall make the trick.



On 14 Feb 2006 at 17:01, Ita.Cirovic-Donev at hypo-alpe-a wrote:

To:             	r-help at stat.math.ethz.ch
From:           	Ita.Cirovic-Donev at hypo-alpe-adria.com
Date sent:      	Tue, 14 Feb 2006 17:01:12 +0100
Subject:        	[R] Inf values in a matrix
> 
> 
> 
> 
> Hello,
> 
> I have some Inf values in a matrix, but I don't want to replace them
> with some value but rather remove the rows that contain the Inf
> values. Also I would like to record the rows which were removed. Is
> there an easy way to do this instead of writing loops over the matrix?
> Thanks.
> 
> Ita Cirovic Donev
> 
> ______________________________________________
> R-help at 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
Petr Pikal
petr.pikal at precheza.cz

Ita.Cirovic-Donev at hypo-alpe-adria.com wrote:
> 
> 
> 
> Hello,
> 
> I have some Inf values in a matrix, but I don't want to replace them
with
> some value but rather remove the rows that contain the Inf values. Also I
> would like to record the rows which were removed. Is there an easy way to
> do this instead of writing loops over the matrix? Thanks.
> 
> Ita Cirovic Donev
> 
> ______________________________________________
> R-help at 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

Example:

  A <- matrix(1:100, 10)
  A[cbind(3:4, 5:6)] <- Inf
  recorded <- which(apply(A, 1, function(x) any(is.infinite(x))))
  A[-recorded,]


Uwe Ligges