AW: [R] Compare rows of two matrices

[TEMPL Matthias]

Excellent. That was very helpful. Now I have full control about my NA´s  :-)
Thank you very much!!!
Matthias

> 
> Here is an another way
> 
>    count <- is.na(x) + is.na(y)
>    which( count == 1, arr.ind=TRUE )
> 
> 'count' gives you the number of missing values at for each 
> row and column. Then you can find out how many occurances of 
> both missing, none missing and one missing. 
>  
> 
> 
> On Mon, 2005-02-21 at 15:48 +0100, TEMPL Matthias wrote:
> > Hello,
> > 
> > #I have two matrices, eg.:
> > 
> > y <-  matrix( c(20,  NA,  NA,  45,  50,  19,  32, 101,  10, 
>  22,  NA,  
> > NA,  80,  49,  61, 190), ncol=4 ) x <-  matrix( c(20,  NA,  
> NA,  NA,  
> > 50,  19,  32, 101,  10,  22,  NA,  NA,  80,  49,  61, 190), ncol=4 )
> > 
> > #Whereas x contains all NA´s from y plus some additional 
> NA´s. #I want 
> > to find the index of these additional NA´s. I think, there 
> must be a 
> > very easy way to do this.
> > 
> > #Here are the indices of NA´s in x and y:
> > l1 <- which(is.na(x), arr.ind=TRUE)
> > l2 <- which(is.na(y), arr.ind=TRUE)
> > 
> > #> l1
> > #     [,1] [,2]
> > #[1,]    2    1
> > #[2,]    3    1
> > #[3,]    4    1
> > #[4,]    3    3
> > #[5,]    4    3
> > 
> > #> l2
> > #     row col
> > #[1,]   2   1
> > #[2,]   3   1
> > #[3,]   3   3
> > #[4,]   4   3
> > 
> > #Now I want to find a matrix, which includes the values of 
> l1, without 
> > the rows of l2,
> > #which has equal entities (the index of the additional NA´S).
> > #In this example the result should be row 3 of l1 with the 
> values 4 and 1..
> > #The following code works, but I think there must be a much 
> more elegant way to do this.
> > 
> > l3 <- l1
> > l3 <- cbind( l1, rep(0, nrow(l1)) )
> > num <- 1
> >    
> > for( i in 1:nrow(l1) ){
> >   for( j in 1:nrow(l2) ){
> >     if( l1[i,1] == l2[j,1] & l1[i,2] == l2[j,2]){
> >       l3[i,3] <- 1
> >     }
> >   }
> > }
> > 
> > l4 <- l3[l3[,3]==0, c(1,2)]
> > 
> > #> l4
> > #row col 
> > #  4   1  
> > 
> > I have often such problems like this and I assume, that 
> other people 
> > have similar tasks. My question is: Does anybody know a function in 
> > one package, which compares rows of two matrices like this or have 
> > anybody an idea to do this in a much more elegant way"?
> > 
> > Thank you very much,
> > Matthias
> > 
> > ______________________________________________
> > R-help at 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
> > 
>