reordering the data

i have values as

D=[1 2 3 4 5 6 7 ]

now i want to reorder the data

D1=[3 4 7 1 2 6 5]this is for example,

i want the order to be changed from D,without using randperm function,please help

Answer 1

[Andreas Goser]

What about generating two random numbers as indices and swapping the data of the indices? And then do this in a loop.

clc
D=[1 2 3 4 5 6 7 ]

for k=1:10
    x1=randi(length(D));
    x2=randi(length(D));
    dummy=D(x1);
    D(x1)=D(x2);
    D(x2)=dummy
end

Answer 2

[Junaid]

Second possible way is

D = [1 2 3 4 5 6 7];

declare any temp variable to have the order of indices. For example.

T = [3 4 7 1 2 6 5];

D1 = D(T);

In given example your indices and values are same, but for different values following code will work.

Answer 3

[Jan]

D.E. Knuth has shown some shuffle methods, e.g.:

D1 = D;
for i = 2:numel(D)   % Knuth shuffle in forward direction: 
   w     = ceil(rand * i);   % 1 <= w <= i
   t     = D1(w);
   D1(w) = D1(i);
   D1(i) = t;
end

This is proven to be unbiased and cheaper than using 2 random numbers for swapping. See also: FEX: RPG-lab.

Answer 4

[Sean de Wolski]

Sure:

[~, idx] = sort(rand(size(D)));
D1 = D(idx);