R help - Jul 2008 - Ignore blank columns when reading a row from a table

Hi,

I am extracting data from a table where the rows have different column lengths,
and empty columns have NA in them. Whenever I extract a row with some empty
columns, the resulting vector carries all the NAs. Is there a way to ignore the
empty columns?

Thanks,
-Nina

It depends what you mean by 'ignore'.  Some functions have an na.rm 
argument which throws out NAs before computing the statistic.

if the vector 'x' has NAs, then

x <- x[!is.na(x)]

may be what you're looking for.  This removes NAs from x and reassigns 
the value to x.

naw3 at duke.edu wrote:
> Hi,
> 
> I am extracting data from a table where the rows have different column
lengths,
> and empty columns have NA in them. Whenever I extract a row with some empty
> columns, the resulting vector carries all the NAs. Is there a way to ignore
the
> empty columns?
> 
> Thanks,
> -Nina
> 
> ______________________________________________
> R-help at 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.

Dear Nina,

If you have a matrix X like this

# Data set
set.seed(123)
X=matrix(rnorm(10*5),ncol=5)
X[1,1]<-NA
X[2,1]<-NA
X[1,5]<-NA
X[5,2]<-NA
X

and you'd like to remove the NA values for a particular row (for example row
1), you can try something like:

X[1,!is.na(X[1,])]


Now, if you have a vector "y", you could do:

set.seed(123)
y=c(NA,rnorm(5),NA)
y
y[!is.na(y)]


HTH,

Jorge



On Tue, Jul 1, 2008 at 1:49 PM, <naw3@duke.edu> wrote:
> Hi,
>
> I am extracting data from a table where the rows have different column
> lengths,
> and empty columns have NA in them. Whenever I extract a row with some empty
> columns, the resulting vector carries all the NAs. Is there a way to ignore
> the
> empty columns?
>
> Thanks,
> -Nina
>
> ______________________________________________
> 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.
>
	[[alternative HTML version deleted]]

Em Ter, 2008-07-01 ?s 13:49 -0400, naw3 at duke.edu
escreveu:
> Hi,
> 
> I am extracting data from a table where the rows have different column
lengths,
> and empty columns have NA in them. Whenever I extract a row with some empty
> columns, the resulting vector carries all the NAs. Is there a way to ignore
the
> empty columns?
> 
> Thanks,
> -Nina
Nina

You can use scan() and argument what, if necessary you can use the
argument fill=T to solve a diferent coluns length.
use ?scan to get help




-- 
Bernardo Rangel Tura, M.D,MPH,Ph.D
National Institute of Cardiology
Brazil

P.S. I learn this tip read: "Data Manipulation with R"