R help - Jun 2006 - programming advice

Dear R users

I want to compute Kendall's Tau between two vectors x and y.
But x and y  may have zeros in the same position(s) and I wrote the
following function to be sure to drop out those "double zeros"

"cor.kendall" <- function(x,y) {
  nox <- c()
  noy <- c()
  #
  for (i in 1:length(x)) if (x[i]!= 0 | y[i] != 0)
      nox[length(nox)+1]<- x[i]
  for (i in 1:length(y)) if (x[i]!= 0 | y[i] != 0)
      noy[length(noy)+1]<- y[i]
  #
  res.kendall <- cor.test(nox,noy,method = "kendall",exact=F)
  return(list(x=nox,y=noy,res.kendall,length(nox)))
}

Do you know a more elegant way to achieve the same goal ?
(I'm sure you do : it's a newbie's program actually)

-- 
Fred

Will the following code work for you?
> index<-!(x==0 & y==0)
> x<-x[index]
> y<-y[index]

2006/6/22, Fred JEAN <frederic.jean at
univ-brest.fr>:
> Dear R users
>
> I want to compute Kendall's Tau between two vectors x and y.
> But x and y  may have zeros in the same position(s) and I wrote the
> following function to be sure to drop out those "double zeros"
>
> "cor.kendall" <- function(x,y) {
>   nox <- c()
>   noy <- c()
>   #
>   for (i in 1:length(x)) if (x[i]!= 0 | y[i] != 0)
>       nox[length(nox)+1]<- x[i]
>   for (i in 1:length(y)) if (x[i]!= 0 | y[i] != 0)
>       noy[length(noy)+1]<- y[i]
>   #
>   res.kendall <- cor.test(nox,noy,method = "kendall",exact=F)
>   return(list(x=nox,y=noy,res.kendall,length(nox)))
> }
>
> Do you know a more elegant way to achieve the same goal ?
> (I'm sure you do : it's a newbie's program actually)
>
> --
> Fred
>
> ______________________________________________
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>

-- 
??????
Department of Sociology
Fudan University

>>>>> "Fred" == Fred JEAN <frederic.jean at
univ-brest.fr>
>>>>>     on Thu, 22 Jun 2006 17:58:06 +0200 writes:
    Fred> Dear R users
    Fred> I want to compute Kendall's Tau between two vectors x and y.
    Fred> But x and y  may have zeros in the same position(s) and I wrote the
    Fred> following function to be sure to drop out those "double
zeros"

    "cor.kendall" <- function(x,y) {
      nox <- c()
      noy <- c()
      #
      for (i in 1:length(x)) if (x[i]!= 0 | y[i] != 0)
	  nox[length(nox)+1]<- x[i]
      for (i in 1:length(y)) if (x[i]!= 0 | y[i] != 0)
	  noy[length(noy)+1]<- y[i]
      #
      res.kendall <- cor.test(nox,noy,method = "kendall",exact=F)
      return(list(x=nox,y=noy,res.kendall,length(nox)))
    }
    
    Fred> Do you know a more elegant way to achieve the same goal ?
    Fred> (I'm sure you do : it's a newbie's program actually)

"Ronggui" already helped you with your main question.

Just a note:  
Why are you making the detour of calling cor.test(.)
when  
      cor(nox, noy,  method = "kendall")    

is probably all you need?