R help - Feb 2005 - Compare rows of two matrices

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

> 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.

How about this:

  is.na(x) & !is.na(y)


Jonne.

maybe something like this:

which(is.na(y)!=is.na(x), arr.ind=TRUE)

I hope it helps.

Best,
Dimitris

----
Dimitris Rizopoulos
Ph.D. Student
Biostatistical Centre
School of Public Health
Catholic University of Leuven

Address: Kapucijnenvoer 35, Leuven, Belgium
Tel: +32/16/336899
Fax: +32/16/337015
Web: http://www.med.kuleuven.ac.be/biostat/
     http://www.student.kuleuven.ac.be/~m0390867/dimitris.htm


----- Original Message ----- 
From: "TEMPL Matthias" <Matthias.Templ at statistik.gv.at>
To: <r-help at stat.math.ethz.ch>
Sent: Monday, February 21, 2005 3:48 PM
Subject: [R] Compare rows of two matrices

> 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
>

Here's one way:
> idx <- which(! paste(l1, collapse=":") %in% paste(l2,
collpase=":"))
> l1[idx,]
row col 
  2   1 

Andy
> From:  TEMPL Matthias
> 
> 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
> 
>

Ohh. Now I begin to see. It?s really simple and elegant!
Thank you very much!!!
Matthias

----------------
> maybe something like this:
> 
> which(is.na(y)!=is.na(x), arr.ind=TRUE)
> 
> I hope it helps.
> 
> Best,
> Dimitris
> 
> ----
> Dimitris Rizopoulos
> Ph.D. Student
> Biostatistical Centre
> School of Public Health
> Catholic University of Leuven
> 
> Address: Kapucijnenvoer 35, Leuven, Belgium
> Tel: +32/16/336899
> Fax: +32/16/337015
> Web: http://www.med.kuleuven.ac.be/biostat/
>      http://www.student.kuleuven.ac.be/~m0390867/dimitris.htm
> 
-----------------
> How about this:
> 
>   is.na(x) & !is.na(y)
> 
> 
> Jonne.
> 
-----------------
> 
> ----- Original Message ----- 
> From: "TEMPL Matthias" <Matthias.Templ at statistik.gv.at>
> To: <r-help at stat.math.ethz.ch>
> Sent: Monday, February 21, 2005 3:48 PM
> Subject: [R] Compare rows of two matrices
> 
> 
> > 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
> > 
>

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
>