R help - Apr 2000 - removing NA values from data frame & identification function

Dear people,

1) I have a data frame with named columns.For concreteness, let us say
that I created a data frame from the vectors fee, fi fo, fum by

giant.df <- cbind(fee, fi, fo, fum)

Now, some of the entries in fee, fi fo fum are NAs. I want to remove any
row which contains a NA, thus creating a new, smaller data frame, with the
same column names. This seems like something people would need to do all
the time, but I have been unable to think of a clean way to do it.

Actually, I'm trying to do this because step and stepAIC don't seem to
happy with handling glm objects constructed from data sets containing
NAs. It would be even cooler if this could be done at the level of
read.table, but I don't see a way to do this.

2) Is there a function to compare whether two objects are identical in
every respect?

Thanks for everyone's very valuable help on this list. I'm still a raw
beginner, but perhaps getting a little less raw...

                         Sincerely, Faheem Mitha.

-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at
stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._

On Wed, 19 Apr 2000, Faheem Mitha wrote:
> Dear people,
> 
> 1) I have a data frame with named columns.For concreteness, let us say
> that I created a data frame from the vectors fee, fi fo, fum by
> 
> giant.df <- cbind(fee, fi, fo, fum)
> 
> Now, some of the entries in fee, fi fo fum are NAs. I want to remove any
> row which contains a NA, thus creating a new, smaller data frame, with the
> same column names. This seems like something people would need to do all
> the time, but I have been unable to think of a clean way to do it.
  perhaps

clean.df <- giant.df[apply(giant.df,1,function(z)all(!is.na(z))),]

 would do what you wanted?

 Or, slightly more tersely,

            giant.df[!(apply(is.na(giant.df),1,any)),]
> 
> Actually, I'm trying to do this because step and stepAIC don't seem
to
> happy with handling glm objects constructed from data sets containing
> NAs. It would be even cooler if this could be done at the level of
> read.table, but I don't see a way to do this.
> 

-- 
Ben Bolker                                  bolker at zoo.ufl.edu
Zoology Department, University of Florida   http://www.zoo.ufl.edu/bolker
318 Carr Hall/Box 118525                    tel: (352) 392-5697
Gainesville, FL 32611-8525                  fax: (352) 392-3704

-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at
stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._

Faheem Mitha <faheem at email.unc.edu> writes:
> Dear people,
> 
> 1) I have a data frame with named columns.For concreteness, let us say
> that I created a data frame from the vectors fee, fi fo, fum by
> 
> giant.df <- cbind(fee, fi, fo, fum)
> 
> Now, some of the entries in fee, fi fo fum are NAs. I want to remove any
> row which contains a NA, thus creating a new, smaller data frame, with the
> same column names. This seems like something people would need to do all
> the time, but I have been unable to think of a clean way to do it.
This would seem to do what you want:

giant.df.clean <- na.omit(giant.df) 

or 

subset(giant.df, complete.cases(giant.df))

or

giant.df[complete.cases(giant.df),]


However, this works on data frames and your giant.df is a matrix,
*not* a data frame. Use

giant.df <- data.frame(fee, fi, fo, fum)

and then go for the golden easter eggs...

-- 
   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)             FAX: (+45) 35327907
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at
stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._