[R] median between matrix column

Jessica Streicher j.streicher at micromata.de
Mon Oct 15 16:22:13 CEST 2012


Actually i just saw that i copied the wrong code

apply(m,2,function(x){median(c(x,m[,5]))})

it should be.

Sorry if this confused anyone.

On 15.10.2012, at 15:32, eliza botto wrote:

> 
> Dear Arun and Jessica,
> thnx for your reply. it realy worked out.
> regards
> eliza
> 
> 
>> Date: Mon, 15 Oct 2012 05:55:55 -0700
>> From: smartpink111 at yahoo.com
>> Subject: Re: [R] median between matrix column
>> To: eliza_botto at hotmail.com
>> CC: r-help at r-project.org
>> 
>> HI,
>> May be this helps you (if I understand it correctly):
>> set.seed(1)
>> mat1<-matrix(sample(1:500,160,replace=TRUE),ncol=16)
>> res<-do.call(rbind,lapply(1:ncol(mat1[,-16]),function(i) median(sort(stack(as.data.frame(mat1[,c(i,16)]))[,1]))))
>> res
>> #       [,1]
>> #[1,] 239.0
>> #[2,] 238.0
>> #[3,] 181.5
>> #[4,] 244.5
>> #[5,] 265.0
>> #[6,] 212.0
>> #[7,] 228.5
>> #[8,] 233.0
>> #[9,] 182.5
>> #[10,] 239.5
>> #[11,] 233.5
>> #[12,] 220.0
>> #[13,] 235.0
>> #[14,] 259.0
>> #[15,] 227.0
>> 
>> A.K.
>> 
>> 
>> 
>> 
>> 
>> ----- Original Message -----
>> From: eliza botto <eliza_botto at hotmail.com>
>> To: "r-help at r-project.org" <r-help at r-project.org>
>> Cc: 
>> Sent: Monday, October 15, 2012 8:20 AM
>> Subject: [R] median between matrix column
>> 
>> 
>> Dear useRs,
>> 
>> 1.    how to calculate single median value for two columns of a matrix?
>> 2.    i have a matrix of 16 columns and 365 rows, how to calculate median between columns 1 and 16, 2 and 16, 3 and 16, 4 and 16, 5 and 16 till 15th column. is there a loop command to do the said operation?
>> 
>> regards
>> eliza                          
>>    [[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.
>> 
> 		 	   		  
> 	[[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.




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