data.frame-question]

str(TAB3)

First a general comment on posting style, could you please be more
specific about where the error occurs as without this it is very
difficult to identify what the problem is.

Now concerning your problem.  When I tried the code I posted yesterday
I thought it worked fine.  I've tried it again now and found that the
data.frame TAB3 actually only has one column and the names "A", "B"
etc are actually interpreted as the row names.  Since there is only
one column the 'colnames(TAB3) <-' fails when you give it a vector
with two components.  I think that if you display it without renaming
the columns then it still displays the correct results though.  I also
tested it with including NA's and it worked fine.  I'm quite a newbie
myself so I don't know how you can't tell you how to return the result
into a two column data.frame.

For completeness, here is the code I used to test.

Name <- c(rep("A", 3), rep("B", 5), "C")
Number <- rep(1, 8)
Number[9] <- NA
TAB1 <- data.frame(Name, Number)
TAB1

  Name Number
1    A      1
2    A      1
3    A      1
4    B      1
5    B      1
6    B      1
7    B      1
8    B      1
9    C     NA

TAB3 <- with(TAB1, tapply(Number, Name, sum, na.rm=TRUE))
TAB3

A B C 
3 5 0 

TAB3 <- as.data.frame(TAB3)
TAB3

  TAB3
A    3
B    5
C    0

colnames(TAB3) <- c("Name_singular", "Sum")

Error in "dimnames<-.data.frame"(`*tmp*`, value = list(c("A", "B", "C"
: 
        invalid 'dimnames' given for data frame

TAB3

  TAB3
A    3
B    5
C    0

str(TAB3)

`data.frame':   3 obs. of  1 variable:
 $ TAB3: num [, 1:3] 3 5 0
  ..- attr(*, "dimnames")=List of 1
  .. ..$ : chr  "A" "B" "C"

version

         _              
platform i386-pc-mingw32
arch     i386           
os       mingw32        
system   i386, mingw32  
status                  
major    2              
minor    2.0            
year     2005           
month    10             
day      06             
svn rev  35749          
language R              



-----Original Message-----
From: Michael Graber [mailto:michael_graber at gmx.de] 
Sent: 27 October 2005 12:43 AM
To: TobiasBr at Taquanta.com
Subject: Re: Re: [R] data.frame-question]

This is what I am looking for, but I still get an error message, that
my arguments are not of the same length. How can I avoid this error
message? Maybe I should add, that there are also NA??s in the second
column, but I tried to ignore them by na.rm=TRUE.

Thanks in advance,

Michael Graber



Michael Graber schrieb:

--------------------------------------------------------------------
-- --

Betreff:
RE: [R] data.frame-question
Von:
"Brandt, T. (Tobias)" <TobiasBr at Taquanta.com>
Datum:
Wed, 26 Oct 2005 09:20:23 +0200
An:
"'r-help at stat.math.ethz.ch'" <r-help at stat.math.ethz.ch>

An:
"'r-help at stat.math.ethz.ch'" <r-help at stat.math.ethz.ch>
CC:
'Michael Graber' <michael_graber at gmx.de>


Is

TAB3 <- as.data.frame(with(TAB1, tapply(Number, Name, sum)))
colnames(TAB3) <- c("Name_singular", "Sum")

what you are looking for?



-----Original Message-----
From: r-help-bounces at stat.math.ethz.ch 
[mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Michael
Graber Sent: 25 October 2005 09:45 PM To: R-Mailingliste Subject:
[R] data.frame-question

Dear R-List,
I am very new to R and programming itself, so my question may be
easy to answer for you. I tried a lot and read through the manuals,
but I still have the following problem: I have 2 data-frames:
Number<-as.numeric (Number) Name<-as.character (Name)
TAB1<-data.frame (Name,Number) - it looks like this:- Name Number A
2 A 3 A 6 B 8 B 12 B 7 C 8 D 90 E 12 E 45 ...
Name_singular<-as.character (Name_singular) TAB2<-data.frame
(Name_singular) # it looks like this: Name_singular A B C D E -My
result should be a data-frame, where the first column is
Name_singular and the second column should be the sum of the numbers
where Name ==Name_singular.- For example:

TAB3:
Name_singular Sum
A 11
B 27
...
- I tried it with for-loops, but I think there must be an easier
way.- I would be very grateful for your help,


Michael Graber

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