[R] How to delete an entire row, if a specific colum has the value of "#VALUE!"

[David Winsemius]

On Apr 23, 2011, at 2:49 AM, David Winsemius wrote:

>
> On Apr 22, 2011, at 10:35 PM, empyrean wrote:
>
>> I am importing CSV data with thousands of rows, if any row contains  
>> an error
>> from excel, the whole program crashes, so i need to delete all rows  
>> with the
>> value of #VALUE!, all other values are non-numeric...
>>
>> I've tried a bunch of strategies, but nothing seems to work.
>
>
>
> A set of error targets:
> > lines <- textConnection("a,#NAME?,b
> + #DIV/0!,b,v
> + #VALUE!,bb,nn")
> > dat <- read.table(lines, sep="," , header=FALSE, comment="")
> > dat
>       V1     V2 V3
> 1       a #NAME?  b
> 2 #DIV/0!      b  v
> 3 #VALUE!     bb nn
>
> # This will turn all the #VALUE!'s into <NA>'s
> > is.na(dat) <- dat == "#VALUE!"
> > dat
>       V1     V2 V3
> 1       a #NAME?  b
> 2 #DIV/0!      b  v
> 3    <NA>     bb nn

If you still want to remove rows rather than use R's missing value  
facilities, here's a way to eliminate the rows in that result with  
"#NAME?", namely to only return the rows that don't have it and then  
to rbind the results:

 > do.call("rbind", apply(dat,1,function(x) if (!"#NAME?" %in% x)  
{x} ) )
      V1        V2   V3
[1,] "#DIV/0!" "b"  "v"
[2,] NA        "bb" "nn"

(You need to learn to read R code from the inside out.)

David Winsemius, MD
West Hartford, CT