[R] Excluding rows from a matrix

[Peter Dalgaard BSA]

José Ernesto Jardim <ernesto at ipimar.pt> writes:

> Hi
> 
> I have a matrix (4 x 950) and I want to remove 3 rows, where the values
> from the first column are 713, 714 and 715. I can select the rows, one
> by one, with
> 
> mat[mat$first==713,]
> mat[mat$first==714,]
> ...
> 
> but I'm unable to (i) select the 3 rows at once, (ii) select the matrix
> excluding those rows.
> 
> How can I do it ?

Um, if you can do that, then mat is a dataframe, not a matrix!

Something like

mat[!(mat$first %in% 713:715),]

would seem to work.

-- 
   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)             FAX: (+45) 35327907
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