After getting great help here to randomize a matrix without repetitions in rows and columns (Fixed values not repeated over column and row) I have another question concerning a modification.
So, first start with what has been done: I wanted a matrix with randomized rows and columns without duplications in each (row wise and column) wise. Again thanks to the great help here this is the code by jdobres (https://stackoverflow.com/users/6436545/jdobres) I ended up using:
# number of rows and columns
n <- 10
# create ordered rows and columns
ordered.by.row <- matrix(1:n, n, n)
ordered.by.col <- matrix(1:n, n, n, byrow = T)
# offset the rows and columns relative to each other.
# no row or column has a repeated value, but the values are still ordered
offset <- (ordered.by.row + ordered.by.col) %% n + 1
# shuffle the columns, then shuffle the rows, this produces a randomized matrix
# 'shuffle.row' is the final, randomized matrix
set.seed(1222) # change this to change randomization
shuffle.col <- offset[,sample(1:n, n, replace = F)]
shuffle.row <- shuffle.col[sample(1:n, n, replace = F), ]
# verify solution
any(apply(shuffle.row, 1, function(r)any(duplicated(r)))) # FALSE
any(apply(shuffle.row, 2, function(r)any(duplicated(r)))) # FALSE
> # create ordered rows and columns
ordered.by.row <- matrix(1:n, n, n)
ordered.by.col <- matrix(1:n, n, n, byrow = T)
# offset the rows and columns relative to each other.
# no row or column has a repeated value, but the values are still ordered
offset <- (ordered.by.row + ordered.by.col) %% n + 1
# shuffle the columns, then shuffle the rows, this produces a randomized matrix
# 'shuffle.row' is the final, randomized matrix
set.seed(1222) # change this to change randomization
shuffle.col <- offset[,sample(1:n, n, replace = F)]
shuffle.row <- shuffle.col[sample(1:n, n, replace = F), ]
# verify solution
any(apply(shuffle.row, 1, function(r)any(duplicated(r)))) # FALSE
any(apply(shuffle.row, 2, function(r)any(duplicated(r)))) # FALSE
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
[1,] 1 10 6 9 2 8 3 5 7 4
[2,] 3 2 8 1 4 10 5 7 9 6
[3,] 7 6 2 5 8 4 9 1 3 10
[4,] 9 8 4 7 10 6 1 3 5 2
[5,] 10 9 5 8 1 7 2 4 6 3
[6,] 2 1 7 10 3 9 4 6 8 5
[7,] 8 7 3 6 9 5 10 2 4 1
[8,] 6 5 1 4 7 3 8 10 2 9
[9,] 5 4 10 3 6 2 7 9 1 8
[10,] 4 3 9 2 5 1 6 8 10 7
However I have the issue now that I want my first rows (lets say row 1,2,3) fixed in a specific order. Nevertheless I need new rows 4 to 10 to again be randomized and without duplicates (also no duplicates concerning rows 1-3)!
So for example I have 3 rows like this:
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
[1,] 8 7 3 6 9 5 10 2 4 1
[2,] 6 5 1 4 7 3 8 10 2 9
[3,] 5 4 10 3 6 2 7 9 1 8
BUT for the next 7 rows I want randomized but not duplicated (in any row or column) values without changing the first rows...
Any ideas? I cannot figure out how to exclude the ones I want to stay (row 1-3) from shuffeling but still have no duplicates in the rest of the rows and columns...
Your help would be again much appreciated!
EDIT:
Thank you very much Moody_Mudskipper for you help! This what the solution looks like using my (fake) data:
mat<-as.matrix(first.rows)
nkeep <- 3
mat_shuffled <- mat[c(1:nkeep,sample((nkeep+1):nrow(mat),replace=FALSE)),]
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
row1 1 4 7 6 5 3 2 8 9 10
row2 10 7 3 2 1 4 5 9 8 6
row3 9 2 4 3 5 7 10 1 6 5
10 7 9 6 8 2 5 4 3 1
1 10 8 4 7 3 5 2 6 9
10 6 4 1 8 3 7 2 5 9
2 5 7 8 9 6 1 3 4 10
2 1 10 4 8 9 3 6 5 7
8 5 3 2 4 1 10 7 6 9
6 1 5 4 2 10 3 8 7 9
THANKY YOU!!
SEE Constructing a randomised matrix with no duplicates but fixed partial input FOR A SOLUTION BY FERNANDO THAT ALSO KEEPS THE VALUES IN COLUMNS UNIQUE
