Using a matrix as an index of another matrix

Hello everybody, I need some help please!

I am trying to sort a matrix (x) and go back to the original order based on the index matrix (idx2).

a = 30.0;

b = 100.0;

for i=1:5

x = (b-a).*rand(5,5) + a;

x = round(x,1);

end

[y, idx2] = sort(x, 2);

Thank you in advance

Answer 1

[Steven Lord]

Take some shuffled data.

r = randperm(10)

r = 1×10

4 9 6 2 1 5 7 8 3 10

Now sort it.

[sortedData, indices] = sort(r)

sortedData = 1×10

1 2 3 4 5 6 7 8 9 10

indices = 1×10

5 4 9 1 6 3 7 8 2 10

We can get back to r from sortedData using the indices.

recreatedR(indices) = sortedData

recreatedR = 1×10

4 9 6 2 1 5 7 8 3 10

Let's check.

isequal(r, recreatedR)

ans = logical
   1

We could also recreate sortedData from r using indices.

isequal(sortedData, r(indices))

ans = logical
   1

[Amine Alrharad]

Hello,

Using arrays it worked, but with matrix is not giving the same order.