R help - May 2008 - request: which integer in each column is in majority

Respected R helpers/ users
I am one of the new R user. I have a problem regarding to know which of the
integer in each column of the following matrix is in majority. I want to know
that integer e.g. in the first column 1 is in majority. Similarly in the third
column 4 is in majority. So what is the suitable way to get the desired integer
for each column. I am looking for some kind reply. Thanks
example:
> x=matrix(c(1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,4,1,2,3,3),ncol=4)
> x
     [,1] [,2] [,3] [,4]
[1,]    1    2    3    4
[2,]    1    2    4    1
[3,]    1    3    4    2
[4,]    2    3    4    3
[5,]    2    3    4    3

 
best regards

Muhammad Azam 
Ph.D. Student 
Department of Medical Statistics, 
Informatics and Health Economics 
University of Innsbruck, Austria 


      
	[[alternative HTML version deleted]]

try this:
> x
     [,1] [,2] [,3] [,4]
[1,]    1    2    3    4
[2,]    1    2    4    1
[3,]    1    3    4    2
[4,]    2    3    4    3
[5,]    2    3    4    3
> apply(x, 2,
function(.col)dimnames(table(.col))[[1]][which.max(table(.col))])
[1] "1" "3" "4"
"3"
>

On Wed, May 28, 2008 at 5:23 AM, Muhammad Azam <mazam72@yahoo.com> wrote:
> Respected R helpers/ users
> I am one of the new R user. I have a problem regarding to know which of the
> integer in each column of the following matrix is in majority. I want to
> know that integer e.g. in the first column 1 is in majority. Similarly in
> the third column 4 is in majority. So what is the suitable way to get the
> desired integer for each column. I am looking for some kind reply. Thanks
> example:
> > x=matrix(c(1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,4,1,2,3,3),ncol=4)
> > x
>     [,1] [,2] [,3] [,4]
> [1,]    1    2    3    4
> [2,]    1    2    4    1
> [3,]    1    3    4    2
> [4,]    2    3    4    3
> [5,]    2    3    4    3
>
>
> best regards
>
> Muhammad Azam
> Ph.D. Student
> Department of Medical Statistics,
> Informatics and Health Economics
> University of Innsbruck, Austria
>
>
>
>        [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help@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<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]]

Muhammad Azam wrote:
> Respected R helpers/ users
> I am one of the new R user. I have a problem regarding to know which of the
integer in each column of the following matrix is in majority. I want to know
that integer e.g. in the first column 1 is in majority. Similarly in the third
column 4 is in majority. So what is the suitable way to get the desired integer
for each column. I am looking for some kind reply. Thanks
> example:
>> x=matrix(c(1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,4,1,2,3,3),ncol=4)
>> x
>      [,1] [,2] [,3] [,4]
> [1,]    1    2    3    4
> [2,]    1    2    4    1
> [3,]    1    3    4    2
> [4,]    2    3    4    3
> [5,]    2    3    4    3
> 
Probably bad but working example:

apply(x, 2, function(x) as.numeric(names(which.max(table(x)))[1]))


Uwe Ligges


> best regards
> 
> Muhammad Azam 
> Ph.D. Student 
> Department of Medical Statistics, 
> Informatics and Health Economics 
> University of Innsbruck, Austria 
> 
> 
>       
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> 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.

Muhammad Azam:
> I am one of the new R user. I have a problem regarding to know which of
> the integer in each column of the following matrix is in majority. I want
> to know that integer e.g. in the first column 1 is in majority.
>
>> x=matrix(c(1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,4,1,2,3,3),ncol=4)
>> x
> [,1] [,2] [,3] [,4]
> [1,] ? ?1 ? ?2 ? ?3 ? ?4
> [2,] ? ?1 ? ?2 ? ?4 ? ?1
> [3,] ? ?1 ? ?3 ? ?4 ? ?2
> [4,] ? ?2 ? ?3 ? ?4 ? ?3
> [5,] ? ?2 ? ?3 ? ?4 ? ?3
As long as the matrix only contains integers, the following should work:

apply(x, 2, function(z) which.max(tabulate(z)) )

Output: 1 3 4 3

-- 
Karl Ove Hufthammer