rearrange a list multiple times with specific patterns and save all the outputs in a nested list

[hnguyen22]

I posted on Stackoverflow but this question has not gained much visibility. Original post here: https://stackoverflow.com/questions/71789201/rearrange-a-list-multiple-times-with-specific-patterns-and-save-all-the-outputs
I'd like to create 15 extra lists from an original list L using a circulant matrix of patterns with the following custom function.

circ_list <- function(L, patterns){
  M <- vector(mode = 'list', length = nrow(patterns))
  if (patterns == patterns[1,]){
    M[j,] <- L
  }
  else {
    for (i in 2:nrow(patterns)) {
      M[j,] <- L[patterns[i,]] 
    }
  }
}

What I did was:

1. Create an empty list M to hold all the outputs
2. Loop through the patterns row by row, at row 1 of patterns, fill M's nested list 1 with the original list L.
3. Continue the loop, at row 2 of patterns, fill M's nested list 2 with a shifted version of L, as defined in the second row of patterns, and so on.

I got an error

circ_list(lst1, patterns)
Warning in if (patterns == patterns[1, ]) { :
  the condition has length > 1 and only the first element will be used
Error in M[j, ] <- L : object 'j' not found

To manually create each of the 15 extra lists

lst2 <- lst1[patterns[2,]]
lst3 <- lst1[patterns[3,]]

list(p4.b4 = structure(0:3, .Dim = c(2L, 2L)), p1.b1 = structure(1:4, .Dim = c(2L, 
2L)), p1.b2 = structure(2:5, .Dim = c(2L, 2L)), p1.b3 = structure(12:15, .Dim = c(2L, 
2L)), p1.b4 = structure(7:10, .Dim = c(2L, 2L)), p2.b1 = structure(10:13, .Dim = c(2L, 
2L)), p2.b2 = structure(5:8, .Dim = c(2L, 2L)), p2.b3 = structure(6:9, .Dim = c(2L, 
2L)), p2.b4 = structure(11:14, .Dim = c(2L, 2L)), p3.b1 = structure(10:13, .Dim = c(2L, 
2L)), p3.b2 = structure(5:8, .Dim = c(2L, 2L)), p3.b3 = structure(3:6, .Dim = c(2L, 
2L)), p3.b4 = structure(1:4, .Dim = c(2L, 2L)), p4.b1 = structure(2:5, .Dim = c(2L, 
2L)), p4.b2 = structure(5:8, .Dim = c(2L, 2L)), p4.b3 = structure(4:7, .Dim = c(2L, 
2L)))

> dput(lst3)
list(p4.b3 = structure(4:7, .Dim = c(2L, 2L)), p4.b4 = structure(0:3, .Dim = c(2L, 
2L)), p1.b1 = structure(1:4, .Dim = c(2L, 2L)), p1.b2 = structure(2:5, .Dim = c(2L, 
2L)), p1.b3 = structure(12:15, .Dim = c(2L, 2L)), p1.b4 = structure(7:10, .Dim = c(2L, 
2L)), p2.b1 = structure(10:13, .Dim = c(2L, 2L)), p2.b2 = structure(5:8, .Dim = c(2L, 
2L)), p2.b3 = structure(6:9, .Dim = c(2L, 2L)), p2.b4 = structure(11:14, .Dim = c(2L, 
2L)), p3.b1 = structure(10:13, .Dim = c(2L, 2L)), p3.b2 = structure(5:8, .Dim = c(2L, 
2L)), p3.b3 = structure(3:6, .Dim = c(2L, 2L)), p3.b4 = structure(1:4, .Dim = c(2L, 
2L)), p4.b1 = structure(2:5, .Dim = c(2L, 2L)), p4.b2 = structure(5:8, .Dim = c(2L, 
2L)))

and so on.

This is the original list

> dput(lst1)
list(p1.b1 = structure(1:4, .Dim = c(2L, 2L)), p1.b2 = structure(2:5, .Dim = c(2L, 
2L)), p1.b3 = structure(12:15, .Dim = c(2L, 2L)), p1.b4 = structure(7:10, .Dim = c(2L, 
2L)), p2.b1 = structure(10:13, .Dim = c(2L, 2L)), p2.b2 = structure(5:8, .Dim = c(2L, 
2L)), p2.b3 = structure(6:9, .Dim = c(2L, 2L)), p2.b4 = structure(11:14, .Dim = c(2L, 
2L)), p3.b1 = structure(10:13, .Dim = c(2L, 2L)), p3.b2 = structure(5:8, .Dim = c(2L, 
2L)), p3.b3 = structure(3:6, .Dim = c(2L, 2L)), p3.b4 = structure(1:4, .Dim = c(2L, 
2L)), p4.b1 = structure(2:5, .Dim = c(2L, 2L)), p4.b2 = structure(5:8, .Dim = c(2L, 
2L)), p4.b3 = structure(4:7, .Dim = c(2L, 2L)), p4.b4 = structure(0:3, .Dim = c(2L, 
2L)))

This is the reference

pattern_o <- names(lst1)
circ<-function(x) { 
    n<-length(x)
    matrix(x[matrix(1:n,n+1,n+1,byrow=T)[c(1,n:2),1:n]],n,n)
}

patterns <-  circ(pattern_o)
> head(patterns)
     [,1]    [,2]    [,3]    [,4]    [,5]    [,6]    [,7]    [,8]    [,9]    [,10]   [,11]   [,12]   [,13]   [,14]   [,15]   [,16]  
[1,] "p1.b1" "p1.b2" "p1.b3" "p1.b4" "p2.b1" "p2.b2" "p2.b3" "p2.b4" "p3.b1" "p3.b2" "p3.b3" "p3.b4" "p4.b1" "p4.b2" "p4.b3" "p4.b4"
[2,] "p4.b4" "p1.b1" "p1.b2" "p1.b3" "p1.b4" "p2.b1" "p2.b2" "p2.b3" "p2.b4" "p3.b1" "p3.b2" "p3.b3" "p3.b4" "p4.b1" "p4.b2" "p4.b3"
[3,] "p4.b3" "p4.b4" "p1.b1" "p1.b2" "p1.b3" "p1.b4" "p2.b1" "p2.b2" "p2.b3" "p2.b4" "p3.b1" "p3.b2" "p3.b3" "p3.b4" "p4.b1" "p4.b2"
[4,] "p4.b2" "p4.b3" "p4.b4" "p1.b1" "p1.b2" "p1.b3" "p1.b4" "p2.b1" "p2.b2" "p2.b3" "p2.b4" "p3.b1" "p3.b2" "p3.b3" "p3.b4" "p4.b1"
[5,] "p4.b1" "p4.b2" "p4.b3" "p4.b4" "p1.b1" "p1.b2" "p1.b3" "p1.b4" "p2.b1" "p2.b2" "p2.b3" "p2.b4" "p3.b1" "p3.b2" "p3.b3" "p3.b4"
[6,] "p3.b4" "p4.b1" "p4.b2" "p4.b3" "p4.b4" "p1.b1" "p1.b2" "p1.b3" "p1.b4" "p2.b1" "p2.b2" "p2.b3" "p2.b4" "p3.b1" "p3.b2" "p3.b3"

The circ function was from https://stackoverflow.com/questions/15795318/efficient-way-to-create-a-circulant-matrix-in-r

Thanks a lot for any leads.

[nirgrahamuk]

@hnguyen22

lst2 <- lst1[patterns[2,]]
lst3 <- lst1[patterns[3,]]

seems like you want :

list_of_lists <- purrr::map(1:16,~lst1[patterns[.x,]])