r - Find the indices of top n elements in a row after ignoring selected indices -

i have dataframe df1 , list l1 :

df1 <- data.frame(c1 = c(4.2, 1.2, 3.0) , c2 = c(2.3, 1.8, 12.0 ) ,c3 = c(1.2, 3.2, 2.0 ) , c4 = c(2.2, 1.9, 0.9) ) l1 <- list(x1 = c(2,4) ,x2 = c(3) ,x3 = c(2)) 

where l1 contains list of indices ignore in df1. now, want find indices of top 2 (can higher) elements after excluding indices in list l1 every row. actual data has more rows , columns. so, expected output :

[1,]    1 3 [2,]    2 4 [3,]    1 3 

where df1 :

      c1   c2  c3  c4 1    4.2  2.3 1.2 2.2 2    1.2  1.8 3.2 1.9 3    3.0 12.0 2.0 0.9 

if indices can in order of values of placeholders, helpful. expected output :

 [1,]    1 3  [2,]    4 2  [3,]    1 3 

we can use rank

lapply(seq_len(nrow(df1)), function(i) {       x1 <- unlist(df1[i,])       i2 <- l1[[i]]       i3 <- seq_along(x1) %in% i2       which(rank(-x1*na^i3) %in% 1:2) }) #[[1]] #[1] 1 3  #[[2]] #[1] 2 4  #[[3]] #[1] 1 3 

update

if need in order

lapply(seq_len(nrow(df1)), function(i) {   x1 <- unlist(df1[i,])   i2 <- l1[[i]]   i3 <- seq_along(x1) %in% i2   i4 <- which(rank(-x1*na^i3) %in% 1:2)   i4[order(-x1[i4])]            }) #[[1]] #[1] 1 3  #[[2]] #[1] 4 2  #[[3]] #[1] 1 3