Hello,
I have this list of 2-d arrays:
$`0`
k d
[1,] 0.2011962 4.019537
[2,] 0.2020706 5.722719
[3,] 0.2029451 7.959612
$`1`
k d
[1,] 0.3148325 2.606903
[2,] 0.3160287 3.806665
[3,] 0.3172249 5.419222
$`2`
k d
[1,] 0.2332536 4.949390
[2,] 0.2342188 7.115258
[3,] 0.2351840 9.955909
which I need to transform into a data frame like this one:
k d group
[1,] 0.2011962 4.019537 0
[2,] 0.2020706 5.722719 0
[3,] 0.2029451 7.959612 0
[1,] 0.3148325 2.606903 1
[2,] 0.3160287 3.806665 1
[3,] 0.3172249 5.419222 1
[1,] 0.2332536 4.949390 2
[2,] 0.2342188 7.115258 2
[3,] 0.2351840 9.955909 2
Is there any R function that I can use? I know stack() but it only
works with vectors.
Thank you!
Ernest
how to stack a list of arrays
2 messages · Ernest Adrogué, R. Michael Weylandt
Try this for the given data: you'll have to modify the group label trick a bit if row-numbers aren't even for each element of L, but it's not hard. L <- list(`0` = matrix(rnorm(6), ncol = 2), `1` = matrix(rnorm(6), ncol = 2), `2` = matrix(rnorm(6), ncol = 2)) # Generally it's bad form to use numbers for names cbind(do.call(rbind, L), group = rep(as.double(names(L)), each = nrow(L[[1]])) Good luck, Michael 2011/11/23 Ernest Adrogu? <nfdisco at gmail.com>:
Hello, I have this list of 2-d arrays: $`0` ? ? ? ? ? ? k ? ? ? ?d [1,] 0.2011962 4.019537 [2,] 0.2020706 5.722719 [3,] 0.2029451 7.959612 $`1` ? ? ? ? ? ? k ? ? ? ?d [1,] 0.3148325 2.606903 [2,] 0.3160287 3.806665 [3,] 0.3172249 5.419222 $`2` ? ? ? ? ? ? k ? ? ? ?d [1,] 0.2332536 4.949390 [2,] 0.2342188 7.115258 [3,] 0.2351840 9.955909 which I need to transform into a data frame like this one: ? ? ? ? ? ? k ? ? ? ?d group [1,] 0.2011962 4.019537 ? ? 0 [2,] 0.2020706 5.722719 ? ? 0 [3,] 0.2029451 7.959612 ? ? 0 [1,] 0.3148325 2.606903 ? ? 1 [2,] 0.3160287 3.806665 ? ? 1 [3,] 0.3172249 5.419222 ? ? 1 [1,] 0.2332536 4.949390 ? ? 2 [2,] 0.2342188 7.115258 ? ? 2 [3,] 0.2351840 9.955909 ? ? 2 Is there any R function that I can use? I know stack() but it only works with vectors. Thank you! Ernest
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