try this:
> x <- read.table(textConnection(" value0 value60 value120 value180 value240
> value300
+ 1 -13007 -11707 -11072 -12471 -12838 -13357
+ 2 -12838 -13210 -11176 -11799 -13210 -13845
+ 3 -12880 -11778 -11113 -12439 -13089 -13880
+ 4 -12805 -11653 -11071 -12385 -11561 -13317
+ 5 -12834 -13527 -11067 -11638 -13527 -13873
+ 6 -11068 -11698 -12430 -12430 -12430 -12814
+ 7 -12807 -14068 -11092 -11709 -11607 -13025
+ 8 -12770 -11665 -11061 -12373 -11426 -12805
+ 9 -12988 -11736 -11137 -12570 -13467 -13739
+ 10 -11779 -12873 -12973 -12537 -12973 -11146"), header=TRUE)
> closeAllConnections()
> # generate the indices of 1st&2nd largest in each row
> indx <- apply(x, 1, function(z){
+ order(z, decreasing=TRUE)[1:2]
+ })
> # now print out the data for each row
> for (i in seq(ncol(indx))){
+ cat('row:', i,
+ '1st:', x[i, indx[1,i]], 'col:', colnames(x)[indx[1,i]],
+ '2nd:', x[i, indx[2,i]], 'col:', colnames(x)[indx[2,i]], '\n')
+ }
row: 1 1st: -11072 col: value120 2nd: -11707 col: value60
row: 2 1st: -11176 col: value120 2nd: -11799 col: value180
row: 3 1st: -11113 col: value120 2nd: -11778 col: value60
row: 4 1st: -11071 col: value120 2nd: -11561 col: value240
row: 5 1st: -11067 col: value120 2nd: -11638 col: value180
row: 6 1st: -11068 col: value0 2nd: -11698 col: value60
row: 7 1st: -11092 col: value120 2nd: -11607 col: value240
row: 8 1st: -11061 col: value120 2nd: -11426 col: value240
row: 9 1st: -11137 col: value120 2nd: -11736 col: value60
row: 10 1st: -11146 col: value300 2nd: -11779 col: value0
>
>
On Fri, Jul 23, 2010 at 9:20 PM, <mpw...@illinois.edu> wrote:
> I have a data frame with a couple million lines and want to retrieve the
> largest and second largest values in each row, along with the label of the
> column these values are in. For example
>
> row 1
> strongest=-11072
> secondstrongest=-11707
> strongestantenna=value120
> secondstrongantenna=value60
>
> Below is the code I am using and a truncated data.frame. Retrieving the
> largest value was easy, but I have been getting errors every way I have tried
> to retrieve the second largest value. I have not even tried to retrieve the
> labels for the value yet.
>
> Any help would be appreciated
> Mike
>
>
>> data<-data.frame(value0,value60,value120,value180,value240,value300)
>> data
> value0 value60 value120 value180 value240 value300
> 1 -13007 -11707 -11072 -12471 -12838 -13357
> 2 -12838 -13210 -11176 -11799 -13210 -13845
> 3 -12880 -11778 -11113 -12439 -13089 -13880
> 4 -12805 -11653 -11071 -12385 -11561 -13317
> 5 -12834 -13527 -11067 -11638 -13527 -13873
> 6 -11068 -11698 -12430 -12430 -12430 -12814
> 7 -12807 -14068 -11092 -11709 -11607 -13025
> 8 -12770 -11665 -11061 -12373 -11426 -12805
> 9 -12988 -11736 -11137 -12570 -13467 -13739
> 10 -11779 -12873 -12973 -12537 -12973 -11146
>> #largest value in the row
>> strongest<-apply(data,1,max)
>>
>>
>> #second largest value in the row
>> n<-function(data)(1/(min(1/(data[1,]-max(data[1,]))))+ (max(data[1,])))
>> secondstrongest<-apply(data,1,n)
> Error in data[1, ] : incorrect number of dimensions
>>
>
> ______________________________________________
> 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.
>
--
Jim Holtman
Cincinnati, OH
+1 513 646 9390
What is the problem that you are trying to solve?
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and provide commented, minimal, self-contained, reproducible code.
