How to Permute the array with specific number?

I want to keep 1,2,6,7,9,10, they will not move

I have this array

b=[1,5,2,8,6,11,7,9,3,10]
P=perms(b);

HOw to use perms for 3,5,8,11 among 6 numbers above?

Answer 1

[Stephen23]

>> b = [1,5,2,8,6,11,7,9,3,10];
>> idx = ~ismember(b,[1,2,6,7,9,10]);
>> mat = repmat(b,factorial(nnz(idx)),1);
>> mat(:,idx) = perms(b(idx))
mat =
    1   11    2    8    6    5    7    9    3   10
    1   11    2    8    6    3    7    9    5   10
    1   11    2    5    6    8    7    9    3   10
    1   11    2    5    6    3    7    9    8   10
    1   11    2    3    6    8    7    9    5   10
    1   11    2    3    6    5    7    9    8   10
    1    8    2   11    6    5    7    9    3   10
    1    8    2   11    6    3    7    9    5   10
    1    8    2    5    6   11    7    9    3   10
    1    8    2    5    6    3    7    9   11   10
    1    8    2    3    6   11    7    9    5   10
    1    8    2    3    6    5    7    9   11   10
    1    5    2   11    6    8    7    9    3   10
    1    5    2   11    6    3    7    9    8   10
    1    5    2    8    6   11    7    9    3   10
    1    5    2    8    6    3    7    9   11   10
    1    5    2    3    6   11    7    9    8   10
    1    5    2    3    6    8    7    9   11   10
    1    3    2   11    6    8    7    9    5   10
    1    3    2   11    6    5    7    9    8   10
    1    3    2    8    6   11    7    9    5   10
    1    3    2    8    6    5    7    9   11   10
    1    3    2    5    6   11    7    9    8   10
    1    3    2    5    6    8    7    9   11   10

[Hang Vu]

Thank you! it's not enough actually, for example, between 1,2 may have all moving numbers

b    = [1,5,2,8,6,11,7,9,3,10];
b    = [1,5,3,2,8,6,11,7,9,10];
b    = [1,5,2,8,6,11,7,3,9,10];

[Stephen23]

How many "moving values" should appear together?:

• minimum zero or one
• maximum two or three or four or no limit

Do you want all permutations (24) as well as all possible combinations of moving different numbers of those values into the "moving" locations ?

[Hang Vu]

3,5,8,11 are moving numbers, and all keep number should follow the order 1,2,6,7,9,10. Yes I want all possible of moving numbers but inside the keeping numbers. Like the example below, between 9,10 is no number. so it will be the perm of moving bnumbers and the space between keeping numbers I think

b    = [1,5,3,2,8,6,11,7,9,10];

[Hang Vu]

To make it easy, I think we can delete 1 and 10. only perm [5,3,2,8,6,11,7,9], since 1, 10 will be stable.

[Stephen23]

Here is a simple but not-very-efficient solution (warning: generates all permutations and discards invalid ones) (note that 1 and 10 have been ignored to make the code simpler):

b = [5,2,8,6,11,7,9,3];
V = [2,6,7,9]; % fixed
P = perms(b);
[X,Y] = ismember(P.',V);
R = reshape(Y(X),[],size(P,1));
D = all(diff(R,1,1)>0);
Z = P(D,:)

Giving:

Z =
     3    11     8     2     6     7     9     5
     3    11     8     2     6     7     5     9
     3    11     8     2     6     5     7     9
     3    11     8     2     5     6     7     9
     3    11     8     5     2     6     7     9
     3    11     2     6     8     7     9     5
     3    11     2     6     8     7     5     9
     3    11     2     6     8     5     7     9
     3    11     2     6     7     8     9     5
  ... lots of lines here
     5     3     2    11     6     7     8     9
     5     3     2    11     6     7     9     8
     5     3     2    11     8     6     7     9
     5     3     2     6    11     8     7     9
     5     3     2     6    11     7     8     9
     5     3     2     6    11     7     9     8
     5     3     2     6     8    11     7     9
     5     3     2     6     8     7    11     9
     5     3     2     6     8     7     9    11
     5     3     2     6     7     8    11     9
     5     3     2     6     7     8     9    11
     5     3     2     6     7    11     8     9
     5     3     2     6     7    11     9     8
     5     3     2     6     7     9    11     8
     5     3     2     6     7     9     8    11
     5     3     2     8     6    11     7     9
     5     3     2     8     6     7    11     9
     5     3     2     8     6     7     9    11
     5     3     2     8    11     6     7     9

[Hang Vu]

Thank you so much! this is what I want!

Answer 2

[Jan]

You did not mention how the output should look like. Perhaps:

b    = [1,5,2,8,6,11,7,9,3,10];
keep = [1,2,6,7,9,10];

move = ~ismember(b, keep);
P    = perms(b(move));
R    = repmat(b, size(P,1), 1);
R(:, move) = P

[Hang Vu]

Thank you Jan! I am sorry, I did not make it more clear. The output may look like b. because I want to list out all posibility of moving for 3, 5, 8, 11 by using perms, and 1, 10 should be in the border and 1,2,6,7,9,10 should follow the order also:

b    = [1,5,2,8,6,11,7,9,3,10];
b    = [1,5,3,2,8,6,11,7,9,10];
b    = [1,5,2,8,6,11,7,3,9,10];

[Stephen23]

@Hang Vu: your examples contradict what you wrote in your question: "I want to keep 1,2,6,7,9,10, they will not move". Clearly in your examples they have moved. Confusing.

[Jan]

@Hang Vu: If I assume, that your examples contain some typos, the output R contains all wanted vectors as rows. So is your problem solved?

[Hang Vu]

Thank you @Jan, I solved my problem. This one is another problem

@Stephen: I mean the order is not changed. if the moving numbers move then you will see the keeping move...

[Jan]

@Hang Vu: I do not understand, what you mean. You solved the problem, but this is another one? Is the problem of your question solved or not?

"if the moving numbers move then you will see the keeping move..." - what does this mean?

Please explain exactly, what you want to achieve.

[Hang Vu]

I am sorry, I miss-understood. I want to list all possible array of the moving numbers between the keeping one