r - 数据框中各列组合的最大总和

Question

我有数据框

df <- data.frame(e_1=c(1,2,3,4,5), e_2=c(1,3,5,7,9), e_3=c(2,4,6,8,1),
                e_4=c(1,2,4,5,7), e_5=c(1,8,9,6,4), Lanes=c(3,4,3,5,4))

我尝试使用:

max(combn(df[,(1:5)],df$Lanes,FUN = function(i) rowSums(df[,(1:5)][i])))

我收到错误

Error in combn(df[, (1:5)], df$Lanes, FUN = function(i) rowSums(df[, (1:5)][i])) : length(m) == 1L is not TRUE

Answer 1

我想你可以尝试使用 combn逐行，例如，

df$comb <- apply(df,1,function(v) max(combn(v[1:5],v["Lanes"],sum)))

以至于

> df
  e_1 e_2 e_3 e_4 e_5 Lanes comb
1   1   1   2   1   1     3    4
2   2   3   4   2   8     4   17
3   3   5   6   4   9     3   20
4   4   7   8   5   6     5   30
5   5   9   1   7   4     4   25