R help - Aug 2008 - Avoiding factors and levels in data frames

Hello all.

I am an experienced R user, I have used R for many years for a wide
variety of applications. However, I keep on running into one obstacle:
I never want factors or levels in my data frames, but I keep on
getting them. Is there any way to globally turn this whole feature of
data frames off? Using options(stringAsFactors=FALSE) does not seem to
work.
Alternatively, if I have a data frame with levels, can I just get rid
of them in that data frame?

Here is an example: I have a large text file, of which part is in the
fixed-width tabular form I need. I created a widths vector and a
column names vector. I then read the file as follows:

raw1<-read.fwf(fn1,widths=widmax,col.names=headermax,stringsAsFactors=FALSE)

But raw1 still has factors! It is an old class data frame:
> is(raw1)
[1] "data.frame" "oldClass"

And it still has levels:
> raw1[1,1]
[1] Gustav wind
229 Levels: - - - - - - -     - - - - WIN       - - - M ... Z INDICATES C

My question is:
1. Can I get rid of the levels in raw1?
2. Even better -- can I stop it getting read in as a data frame with factors?
3. Even better -- can I just tell R to never use factors in my data frames?

Or any other solution that occurs to people -- maybe this is the wrong
way to go about reading in fixed width data in this kind of file.

I would appreciate any help.

Asher

On Sun, 31-Aug-2008 at 12:01PM +0300, Asher Meir wrote:

|> Hello all.
|> 
|> I am an experienced R user, I have used R for many years for a wide
|> variety of applications. However, I keep on running into one obstacle:
|> I never want factors or levels in my data frames, but I keep on
|> getting them. Is there any way to globally turn this whole feature of
|> data frames off? Using options(stringAsFactors=FALSE) does not seem to
|> work.

Have you tried the as.is option?


-- 
~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.   
   ___    Patrick Connolly   
 {~._.~}          		 Great minds discuss ideas    
 _( Y )_  	  	        Middle minds discuss events 
(:_~*~_:) 	       		 Small minds discuss people  
 (_)-(_)  	                           ..... Anon
	  
~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.

Try to add options(stringsAsFactors = FALSE) in your Rprofile.site (in
the etc directory). Using as.is = TRUE seems safer than stringsAsFactors
= FALSE in the read.fwf function. Because as.is is set to FALSE by
default and stringsAsFactors is not set.

HTH,

Thierry


------------------------------------------------------------------------
----
ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Research Institute for Nature
and Forest
Cel biometrie, methodologie en kwaliteitszorg / Section biometrics,
methodology and quality assurance
Gaverstraat 4
9500 Geraardsbergen
Belgium
tel. + 32 54/436 185
Thierry.Onkelinx op inbo.be
www.inbo.be

To call in the statistician after the experiment is done may be no more
than asking him to perform a post-mortem examination: he may be able to
say what the experiment died of.
~ Sir Ronald Aylmer Fisher

The plural of anecdote is not data.
~ Roger Brinner

The combination of some data and an aching desire for an answer does not
ensure that a reasonable answer can be extracted from a given body of
data.
~ John Tukey

-----Oorspronkelijk bericht-----
Van: r-help-bounces op r-project.org [mailto:r-help-bounces op r-project.org]
Namens Asher Meir
Verzonden: zondag 31 augustus 2008 11:02
Aan: r-help op r-project.org
Onderwerp: [R] Avoiding factors and levels in data frames

Hello all.

I am an experienced R user, I have used R for many years for a wide
variety of applications. However, I keep on running into one obstacle:
I never want factors or levels in my data frames, but I keep on
getting them. Is there any way to globally turn this whole feature of
data frames off? Using options(stringAsFactors=FALSE) does not seem to
work.
Alternatively, if I have a data frame with levels, can I just get rid
of them in that data frame?

Here is an example: I have a large text file, of which part is in the
fixed-width tabular form I need. I created a widths vector and a
column names vector. I then read the file as follows:

raw1<-read.fwf(fn1,widths=widmax,col.names=headermax,stringsAsFactors=FA
LSE)

But raw1 still has factors! It is an old class data frame:
> is(raw1)
[1] "data.frame" "oldClass"

And it still has levels:
> raw1[1,1]
[1] Gustav wind
229 Levels: - - - - - - -     - - - - WIN       - - - M ... Z INDICATES
C

My question is:
1. Can I get rid of the levels in raw1?
2. Even better -- can I stop it getting read in as a data frame with
factors?
3. Even better -- can I just tell R to never use factors in my data
frames?

Or any other solution that occurs to people -- maybe this is the wrong
way to go about reading in fixed width data in this kind of file.

I would appreciate any help.

Asher

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