R help - Jun 2005 - Index (which) of last non-NA data in dataframe

Hello,

 

In a dataframe, I want the index if the last non-NA data.   Example:

 

d<-data.frame(matrix(c(1,3,4,2,7,8,1,NA,2),3,3,byrow=TRUE))

 

gives:
> d
  X1 X2 X3

1  1  3  4

2  2  7  8

3  1 NA  2

 

I want a vector that gives me  3 2 3

 

I know about tail and which, but I don't know how not to consider the NA

 

e.g.: last<-tail(d,1,na.rm=TRUE) still gives me a NA
> last
  X1 X2 X3

3  1 NA  2


	[[alternative HTML version deleted]]

If you can be sure that the non-NAs are contiguous, then the following
should work:

sapply(d, function(x) max(which(!is.na(x))))

Andy
> From: Pierre Lapointe
> 
> Hello,
> 
>  
> 
> In a dataframe, I want the index if the last non-NA data.   Example:
> 
>  
> 
> d<-data.frame(matrix(c(1,3,4,2,7,8,1,NA,2),3,3,byrow=TRUE))
> 
>  
> 
> gives:
> 
> > d
> 
>   X1 X2 X3
> 
> 1  1  3  4
> 
> 2  2  7  8
> 
> 3  1 NA  2
> 
>  
> 
> I want a vector that gives me  3 2 3
> 
>  
> 
> I know about tail and which, but I don't know how not to 
> consider the NA
> 
>  
> 
> e.g.: last<-tail(d,1,na.rm=TRUE) still gives me a NA
> 
> > last
> 
>   X1 X2 X3
> 
> 3  1 NA  2
> 
> 
> 	[[alternative HTML version deleted]]
> 
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