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Changing zeros to NAs in a data frame

4 messages · Laura Holt, Sundar Dorai-Raj, Andy Bunn +1 more

Original
Laura Holt
# 
Dear R People:

I have a data frame with some columns that are numeric and some which are 
factors.

There are zeros in the numeric columns and I would like to change them to 
NAs.  However, there are zeros in some of the factor columns, and I would 
like them to be left alone.

Is there a "global" way to do this, please?  I was thinking about use the 
results from "str" but am not sure.

R Version 2.0.0 Windows.

Thanks in advance.
Sincerely,
Laura Holt
mailto: lauraholt_983 at hotmail.com


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Sundar Dorai-Raj
#
Laura Holt wrote:

            

      
      
      
    

        
Let x be your data.frame. Then use:

is.num <- sapply(x, is.numeric)
x[is.num] <- lapply(x[is.num], function(y) ifelse(y == 0, NA, y))

HTH,

--sundar

  
  


  


      

    

    

      
      

        


  

        

      Andy Bunn
    

    

      
      #
    

  


  

      
This isn't pretty but it's a way to do it:

foo <- data.frame(x = c(1,0,1,1,0,2,4), y = as.factor(c(0,2,1,1,0,3,1)))
Zero2NA <- function(x){
    if(is.numeric(x)) { x[x == 0] <- NA; }
    return(x)
}
foo2 <- as.data.frame(lapply(foo, Zero2NA))
foo
foo2

HTH, Andy

            

      
      
      
    

        

      
      
    

  
  


  


      

    

    

      
      

        


  

        

      Brian Ripley
    

    

      
      #
    

  


  

      
On Tue, 16 Nov 2004, Laura Holt wrote:

        

            

      
      
      
    

        
myDF <- data.frame(a=0:4, b=letters[1:5], c=-2:2)
myDF[] <- lapply(myDF, function(x) if(is.numeric(x)) {x[x==0] <- NA; x} else x)

            

      
      
      
    

        
a b  c
1 NA a -2
2  1 b -1
3  2 c NA
4  3 d  1
5  4 e  2