[R] averaging two matrices whilst ignoring missing values

[Moshe Olshansky]

One (awkward) way to do this is:

x <- matrix(c(c(test),c(test2)),ncol=2)
y <- rowMeans(x,na.rm=TRUE)
testave <- matrix(y,nrow=nrow(test))

--- On Tue, 14/7/09, Tish Robertson <tishrobertson at hotmail.com> wrote:

> From: Tish Robertson <tishrobertson at hotmail.com>
> Subject: [R] averaging two matrices whilst ignoring missing values
> To: r-help at r-project.org
> Received: Tuesday, 14 July, 2009, 11:46 AM
> 
> Hi folks,
> 
>  
> 
> I'm trying to do something that seems like it should easy,
> but it apparently isn't.  I have two large matrices,
> both containing a number of missing values at different
> cells. I would like to average these matrices, but the NAs
> are preventing me. I get a "non-numeric argument to binary
> operator" error.  That's the first problem.
> 
>  
> 
> test<-read.csv("test.csv",header=FALSE)
> test2<-read.csv("test2.csv",header=FALSE)
> test_ <- as.matrix(test,na.rm=T) 
> test2_ <- as.matrix(test2,na.rm=T) 
> testave<- (test_+test2_)/2
> 
> ??
> 
>  
> 
> So off the bat I'm doing something wrong.
> 
>  
> 
> How would I replace the missing values in one matrix with
> the corresponding non-missing values in another?  It's
> acceptable to me if I only have one value representing the
> average for a particular coordinate.
> 
>  
> 
> Any help would be appreciated!  
> 
>  
> 
>  
> 
>  
> 
> _________________________________________________________________
> Bing™ finds low fares by predicting when to book. Try it
> now.
> 
> =WLHMTAG&crea=TXT_MTRHPG_Travel_Travel_TravelDeals_1x1
>     [[alternative HTML version deleted]]
> 
> 
> -----Inline Attachment Follows-----
> 
> ______________________________________________
> 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.
>