How to remove duplicate element from matrix ?

I have duplicate matrix S, I need remove the repeated elements from S, and

then put the absent numbers at the end to generate a new matrix X. iI implement remove duplicate element but how we add absent element at the end?

S=[1 11 1 4 3 14 6 11 13 11 7 15 5 9 9 7];

C=unique(S);

[Image Analyst]

That's not a matrix. That's a vector.

Answer 1

[Voss]

Here's one way:

S=[1 11 1 4 3 14  6 11 13  11 7 15  5 9 9 7]

S = 1×16

1 11 1 4 3 14 6 11 13 11 7 15 5 9 9 7

[C,i] = unique(S,'stable')

C = 1×11

1 11 4 3 14 6 13 7 15 5 9

i = 11×1

1 2 4 5 6 7 9 11 12 13

C = [C S(~ismember(1:numel(S),i))]

C = 1×16

1 11 4 3 14 6 13 7 15 5 9 1 11 11 9 7

[Arshub]

@Benjamin Thanks alot for your help.

[Arshub]

@Benjamin can you help me in this state:

I need to use C=[1 3 4 5 6 7 9 11 13 14 15 1 7 9 11 11]

as index to perform permutation of matrix A =[111 222 30 4;50 65 70 83; 10 27 39 40 ; 54 67 72 81 ] by this method:

Substitute A(Ci ) with A (CM×N−i+1).

here i = 1, 2,..., M × N/2.

then i need to make reverse operartion to get the original matrix.

I write the code but when I make reverse operation I coulden't get the original matrix "M" after permutation, Why?

What should I do to get original matrix from permutated matrix?

Note: it is immportant to me use "Substitute A(Ci ) with A (CM×N−i+1)."

to permutate matrix.

%-----------------------------------------------------my rest of code ---------------------------------

A =[111 222 30 4;50 65 70 83; 10 27 39 40 ; 54 67 72 81 ];

[row,col]=size(A);

len=row*col;

A=reshape(A,1,len);

for i =1:len/2

A(C(i))=A(C(len-i+1));% Substitute A(Ci ) with A (CM×N−i+1)., permutation matrix

end

Ab=reshape(A,row,col)

AA=reshape(Ab,1,len);

for i =1:len/2

AA(C(len-i+1))=AA(C(i));% reverse Substitute A (CM×N−i+1) with A(Ci ) to get original matrix

end

AA=reshape(AA,row,col)

[Voss]

@Arshub I modifed my answer after seeing DGM's comment on your other question. I believe this answer is more what this question is looking for.

I recommend you update that other question to clarify the relationship between S and C, specifically that:

S=[1 11 1 4 3 14  6 11 13  11 7 15  5 9 9 7];
[C,i] = unique(S,'stable');
C = [C S(~ismember(1:numel(S),i))];