On a related note, I am trying to do some matching using conditional
statements. These NULL values are being brought in to my data frame as NA,
as expected, but in a conditional if() statement, I cannot compare then to a
integer value, it fails the program. Here is a small snippet of where the
error occurs.

 while(col_loop<1570)
                        {
                                data_filter <- data[c(col_loop)]
                                print(data_filter)
                                if(data_filter == trigger)
                                {
                                        trigger_count <- trigger_count +1
                                }
                                col_loop <- col_loop +1

                        }

Here: trigger_count, and trigger are both integers. The print statement was
debug to see why it was failing and this is what it returned:
<snip>
  V1415
1     0
  V1416
1     0
  V1417
1     1
  V1418
1     1
  V1419
1     1
  V1420
1    NA
Error in if (data_filter == trigger) { :
  missing value where TRUE/FALSE needed

Thanks for any help you can provide.

On Thu, Sep 18, 2008 at 2:12 PM, Hutchinson,David [PYR] <
David.Hutchinson@ec.gc.ca> wrote:

> Try length(na.omit(<the particular data column>))
>
> Here's an example:
>
> data <- runif(100,0,10)
> data[runif(20,0,100)] <- NA
> file.contents <- matrix(data, ncol = 5, byrow = TRUE)
> for (i in 1:5) {
>  print (length(na.omit(file.contents[,i])))
> }
>
>
> -----Original Message-----
> From: r-help-bounces@r-project.org [mailto:r-help-bounces@r-project.org]
> On Behalf Of Jason Thibodeau
> Sent: Thursday, September 18, 2008 10:12 AM
> To: r-help@r-project.org
> Subject: [R] detecting null values in a CSV file
>
> Hello all,
>
> I have a CSV file, that is 2411 columns wide. There are certain
> instances in
> teh file, where null values are located. That is: two commas together,
> without anything in the middle. In a certain section, the only possible
> values are NULL, 0,1,and 2. I need to be able to detect these NULL's and
> be
> able to have them counted. For example, in a frequency table. How can I
> accomplish this?
>
> Thanks in advance for the help.
>
> --
> Jason Thibodeau
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>



-- 
Jason Thibodeau

	[[alternative HTML version deleted]]

