[R] removing zero rows from matrix/table

[Dimitris Rizopoulos]

try this:

mat <- sample(0:1, 49, TRUE)
dim(mat) <- c(7, 7)
mat[c(1,4), ] <- 0

ind <- rowSums(mat == 0) != ncol(mat)
mat[ind, ]


I hope it helps.

Best,
Dimitris

----
Dimitris Rizopoulos
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


----- Original Message ----- 
From: "Patrick Zimmermann" <brassnotdead at googlemail.com>
To: "r-help" <R-help at stat.math.ethz.ch>
Sent: Tuesday, April 22, 2008 11:52 AM
Subject: [R] removing zero rows from matrix/table


> Dear R-community,
> I have matrices/tables of different sizes which may contain rows 
> with
> only zeros. Now I would like to delete these zero lines or create 
> new
> matrices composed only of the non-zero lines. Columns only 
> containing
> zeros I want to preserve.
> Here an example:
>
> [,1] [,2] [,3] [,4] [,5] [,6] [,7]
> [1,] 1 0 1 1 0 0 0
> [2,] 0 0 0 0 0 0 0
> [3,] 1 0 0 0 0 0 0
> [4,] 1 0 1 1 1 1 1
> [5,] 1 0 1 0 1 0 1
> [6,] 0 0 1 1 1 1 1
> [7,] 0 0 0 0 0 0 0
>
> Rows 2 and 7 shall be deleted, but column 2 shall be maintained.
> I believe this should be a simple operation with basic commands, but
> have no idea how to manage it.
> Looking forward do any help,
> Patrick
>
> ______________________________________________
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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.
> 


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