R help - May 2010 - tapply function with NA

Hi R users,

I have a matrix "m" of the type:

m
       X4.20.2010 X4.19.2010   X4.16.2010
[1,]  0.008319468 0.00000000 -0.008250825
[2,]  0.005574136 0.01816118  0.073081608
[3,] -0.047830688 0.01612903 -0.030239833
[4,]           NA         NA           NA
[5,]  0.008746356 0.02848576 -0.025566107
[6,] -0.007990868 0.00000000 -0.026666667

I want to get the sum of each column. Normally I would do:

apply(m,2,sum)

but I get:
> apply(m,2,sum)
X4.20.2010 X4.19.2010 X4.16.2010 
        NA         NA         NA 

This is because of the presence of "NA" in m. How do you the
equivalent of 
> sum(m[1:6,1],na.rm=TRUE)
using apply?

Many thanks!
-- 
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It is exactly the same

tmp <- matrix(1:24,6,4)
tmp[4,] <- NA
tmp
apply(tmp, 2, sum, na.rm=TRUE)

	[[alternative HTML version deleted]]

See ?colSums

On Mon, May 10, 2010 at 12:44 AM, vincent.deluard
<vincent.deluard at trimtabs.com> wrote:
>
> Hi R users,
>
> I have a matrix "m" of the type:
>
> m
> ? ? ? X4.20.2010 X4.19.2010 ? X4.16.2010
> [1,] ?0.008319468 0.00000000 -0.008250825
> [2,] ?0.005574136 0.01816118 ?0.073081608
> [3,] -0.047830688 0.01612903 -0.030239833
> [4,] ? ? ? ? ? NA ? ? ? ? NA ? ? ? ? ? NA
> [5,] ?0.008746356 0.02848576 -0.025566107
> [6,] -0.007990868 0.00000000 -0.026666667
>
> I want to get the sum of each column. Normally I would do:
>
> apply(m,2,sum)
>
> but I get:
>
>> apply(m,2,sum)
> X4.20.2010 X4.19.2010 X4.16.2010
> ? ? ? ?NA ? ? ? ? NA ? ? ? ? NA
>
> This is because of the presence of "NA" in m. How do you the
equivalent of
>> sum(m[1:6,1],na.rm=TRUE)
> using apply?
>
> Many thanks!
> --
> View this message in context:
http://r.789695.n4.nabble.com/tapply-function-with-NA-tp2164930p2164930.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> 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.
>