R help - May 2007 - looking for the na.omit equivalent for a matrix of characters

I have a matrix of characters (actually numbers that have been read in as
numbers), and I'd like to remove the NA.

I'm familiar with na.omit, but is there an equivalent of na.omit when the NA
are the actual characters "NA"?

Thanks,
Andrew

	[[alternative HTML version deleted]]

Since they are characters you can just compare for them.  You did not show
what your data looks like, or what you want to do if there are "NA". 
Do you
want the row removed?  You can use 'apply' to test a row for
"NA":

 > x <- matrix("0",5,5)
> x[1,3] <- x[4,4] <- "NA"
> x
     [,1] [,2] [,3] [,4] [,5]
[1,] "0"  "0"  "NA" "0"  "0"
[2,] "0"  "0"  "0"  "0"  "0"
[3,] "0"  "0"  "0"  "0"  "0"
[4,] "0"  "0"  "0"  "NA" "0"
[5,] "0"  "0"  "0"  "0" 
"0"
> apply(x, 1, function(z) any(z == "NA"))
[1]  TRUE FALSE FALSE  TRUE FALSE
> x[!apply(x, 1, function(z) any(z == "NA")),]
     [,1] [,2] [,3] [,4] [,5]
[1,] "0"  "0"  "0"  "0"  "0"
[2,] "0"  "0"  "0"  "0"  "0"
[3,] "0"  "0"  "0"  "0" 
"0"
>


On 5/28/07, Andrew Yee <andrewjyee@gmail.com>
wrote:
>
> I have a matrix of characters (actually numbers that have been read in as
> numbers), and I'd like to remove the NA.
>
> I'm familiar with na.omit, but is there an equivalent of na.omit when
the
> NA
> are the actual characters "NA"?
>
> Thanks,
> Andrew
>
>        [[alternative HTML version deleted]]
>
> ______________________________________________
> 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.
>


-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem you are trying to solve?

	[[alternative HTML version deleted]]

Surely all you need to do is change them to missing and use na.omit.
e.g.

x <- matrix(letters, 13, 2)
x[4] <- "NA"  # put one in the middle


is.na(x[x == "NA"]) <- TRUE
(x <- na.omit(x))


Bill Venables
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-----Original Message-----
From: r-help-bounces at stat.math.ethz.ch
[mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Andrew Yee
Sent: Tuesday, 29 May 2007 12:50 PM
To: r-help at stat.math.ethz.ch
Subject: [R] looking for the na.omit equivalent for a matrix of
characters

I have a matrix of characters (actually numbers that have been read in
as
numbers), and I'd like to remove the NA.

I'm familiar with na.omit, but is there an equivalent of na.omit when
the NA
are the actual characters "NA"?

Thanks,
Andrew

	[[alternative HTML version deleted]]

______________________________________________
R-help at 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.