[R] reduce the code used by "for"

[Domenico Vistocco]

 > x=c(1,2,NA,3,4,5)*10
 > y=array(rep(x,15),c(5,3,2))
 > dimnames(y)=list(1:5,letters[1:3],NULL)

So to have in the workspace:
 > y
, , 1
   a  b  c
1 10 50 40
2 20 10 50
3 NA 20 10
4 30 NA 20
5 40 30 NA

, , 2
   a  b  c
1 30 NA 20
2 40 30 NA
3 50 40 30
4 10 50 40
5 20 10 50

Then to set the missing in the third row to 0:
 > y[3,,][which(is.na(y[3,,]))]=0

and to set the missing in the other rows to 1:
 > y[-3,,][which(is.na(y[-3,,]))]=1

domenico vistocco


Luis Ridao Cruz wrote:
> R-help,
>
> I have a 3-way array:
>
>   
>> dim(bugvinP)
>>     
> [1] 13 14  3
>
> The array looks something like this (object trimmed for readability)
> , , slag = 1
>
>     ar
>       1994  1995  1996  1997  1998
>   1     NA 0.000 0.000 0.000 0.000
>   2  0.036 0.059 0.027 0.000 0.000
>   3  0.276 0.475 0.491 0.510 0.559
>   10 1.000 1.000 1.000 1.000 1.000
>   11    NA 1.000 1.000    NA 1.000
>   12    NA 1.000 1.000 1.000 1.000
>   13    NA 1.000    NA 1.000    NA
>
> , , slag = 2
>
>     ar
>       1994  1995  1996  1997  1998
>   1     NA 0.000 0.000 0.000 0.000
>   2  0.129 0.029 0.011 0.026 0.000
>   9  1.000 1.000 1.000 1.000 1.000
>   10 1.000 1.000 1.000 1.000 1.000
>   11 1.000 1.000 1.000 1.000 1.000
>   12 1.000 1.000 1.000 1.000 1.000
>   13    NA    NA 1.000 1.000    NA
>
>
> I want to set NAs to 0 if the row names are e.g. 3 
> and 1 otherwise. To implement this I do the following which
> is OK but I wish to find out a more compact/shorter version.
>
> for(i in 1:3)
> {
> bugvinP[,,i] <- ifelse(as.numeric(rownames(bugvinP[,,i])) < 3 &
> is.na(bugvinP[,,i]), 0
> , ifelse(as.numeric(rownames(bugvinP[,,i])) > 9 & is.na(bugvinP[,,i]),
> 1, bugvinP))
> }
>
>
> Thanks in advance
>
>   
>> version
>>     
>                _                           
> platform       i386-pc-mingw32             
> arch           i386                        
> os             mingw32                     
> system         i386, mingw32               
> status                                     
> major          2                           
> minor          6.1                         
> year           2007                        
> month          11                          
> day            26                          
> svn rev        43537                       
> language       R                           
> version.string R version 2.6.1 (2007-11-26)
>   
>
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