R help - Nov 2004 - Create a vector of combinations based on a table column names

I want to create a character vector based on the table (shortened for 
display) below:
Where there are ones in the matrix I want the column name to appear and 
where there are zeros nothing, which would make the vector in this 
shortened case:

combinations <- ("A B","A C","A E H","A F
G","B C D","E G H",A C D E
H","A C D F G")

     no  value  A  B  C  D  E  F  G   H
1    2  3.095  1  1  0  0  0  0  0   0
2    2  1.687  1  0  1  0  0  0  0   0
46   3  3.470  1  0  0  0  1  0  0   1
47   3  1.563  1  0  0  0  0  1  1   0
50   3  6.234  0  1  1  1  0  0  0   0
148  4  3.663  0  0  1  0  1  0  1   1
151  4  3.470  0  0  0  1  1  1  0   1
177  5  5.411  1  0  1  1  1  0  0   1
178  5  6.829  1  0  1  1  0  1  1   0

Question is how to make this not so manually?

---------------------------------------------
Henrik Andersson
Netherlands Institute of Ecology -
Centre for Estuarine and Marine Ecology
P.O. Box 140
4400 AC Yerseke
Phone: +31 113 577473
h.andersson at nioo.knaw.nl
http://www.nioo.knaw.nl/ppages/handersson

Hi,

Here is something that does the job (though I am sure other people will 
find smarter solutions!):


 > samp=matrix(sample(0:1,size=100,replace=TRUE ,prob=c(0.8,0.2)),ncol=10)
 > colnames(samp)<-LETTERS[1:10]
 > unlist(lapply(apply(samp,1,FUN=function(vec) 
colnames(samp)[as.logical(vec)] ),paste,collapse=" "))
  [1] "A F J"   "D I"     "B I"     "A" 
"G H"     "B C E H" "E
H"     "B C E G" "E"
[10] "B C E I"

HTH,

Eric


At 16:40 23/11/2004, Henrik Andersson wrote:
>I want to create a character vector based on the table (shortened for 
>display) below:
>Where there are ones in the matrix I want the column name to appear and 
>where there are zeros nothing, which would make the vector in this 
>shortened case:
>
>combinations <- ("A B","A C","A E
H","A F G","B C D","E G H",A C D E
H","A
>C D F G")
>
>     no  value  A  B  C  D  E  F  G   H
>1    2  3.095  1  1  0  0  0  0  0   0
>2    2  1.687  1  0  1  0  0  0  0   0
>46   3  3.470  1  0  0  0  1  0  0   1
>47   3  1.563  1  0  0  0  0  1  1   0
>50   3  6.234  0  1  1  1  0  0  0   0
>148  4  3.663  0  0  1  0  1  0  1   1
>151  4  3.470  0  0  0  1  1  1  0   1
>177  5  5.411  1  0  1  1  1  0  0   1
>178  5  6.829  1  0  1  1  0  1  1   0
>
>Question is how to make this not so manually?
>
>---------------------------------------------
>Henrik Andersson
>Netherlands Institute of Ecology -
>Centre for Estuarine and Marine Ecology
>P.O. Box 140
>4400 AC Yerseke
>Phone: +31 113 577473
>h.andersson at nioo.knaw.nl
>http://www.nioo.knaw.nl/ppages/handersson
>
>______________________________________________
>R-help at stat.math.ethz.ch mailing list
>https://stat.ethz.ch/mailman/listinfo/r-help
>PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html
Eric Lecoutre
UCL /  Institut de Statistique
Voie du Roman Pays, 20
1348 Louvain-la-Neuve
Belgium

tel: (+32)(0)10473050
lecoutre at stat.ucl.ac.be
http://www.stat.ucl.ac.be/ISpersonnel/lecoutre

If the statistics are boring, then you've got the wrong numbers. -Edward 
Tufte

There has to be a better (more readable) way, but this works...
> set.seed(323)
> foo.df <- data.frame(A = round(runif(5)), B = round(runif(5)), C
round(runif(5)))
> foo.df
  A B C
1 0 1 1
2 1 1 1
3 1 1 1
4 0 1 1
5 1 1 0
> names.list <- lapply( apply( foo.df, 1, function( x ) colnames(
foo.df )[ as.logical( x ) ] ), paste, collapse = ", "
)
> names.vect <- unlist(names.list)
> foo.df
  A B C
1 0 1 1
2 1 1 1
3 1 1 1
4 0 1 1
5 1 1 0
> names.vect
        1         2         3         4         5
   "B, C" "A, B, C" "A, B, C"    "B, C" 
"A, B"
>
Those nested applies make my head hurt.

HTH, Andy

> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch
> [mailto:r-help-bounces at stat.math.ethz.ch]On Behalf Of Henrik Andersson
> Sent: Tuesday, November 23, 2004 10:41 AM
> To: r-help at stat.math.ethz.ch
> Subject: [R] Create a vector of combinations based on a table column
> names
>
>
> I want to create a character vector based on the table (shortened for
> display) below:
> Where there are ones in the matrix I want the column name to appear and
> where there are zeros nothing, which would make the vector in this
> shortened case:
>
> combinations <- ("A B","A C","A E
H","A F G","B C D","E G H",A C D E
> H","A C D F G")
>
>      no  value  A  B  C  D  E  F  G   H
> 1    2  3.095  1  1  0  0  0  0  0   0
> 2    2  1.687  1  0  1  0  0  0  0   0
> 46   3  3.470  1  0  0  0  1  0  0   1
> 47   3  1.563  1  0  0  0  0  1  1   0
> 50   3  6.234  0  1  1  1  0  0  0   0
> 148  4  3.663  0  0  1  0  1  0  1   1
> 151  4  3.470  0  0  0  1  1  1  0   1
> 177  5  5.411  1  0  1  1  1  0  0   1
> 178  5  6.829  1  0  1  1  0  1  1   0
>
> Question is how to make this not so manually?
>
> ---------------------------------------------
> Henrik Andersson
> Netherlands Institute of Ecology -
> Centre for Estuarine and Marine Ecology
> P.O. Box 140
> 4400 AC Yerseke
> Phone: +31 113 577473
> h.andersson at nioo.knaw.nl
> http://www.nioo.knaw.nl/ppages/handersson
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
> http://www.R-project.org/posting-guide.html
>