Obtain the sorted index vector

Suppose a vector with element. in Matlab, I can use the following code to sort the vector in descending order as follow:

y=sort(x,'descend'), for example, x=[0.5; 0.4; 0.6; 0.9], then y=[0.9; 0.6; 0.5; 0.4].

I need to Obtain the sorted index vector. Here it will be z=[4; 3; 1; 2]

I need to find z for any arbitrary sorted vector.

Answer 1

[Bruno Luong]

Use the second output of sort

x=[0.5; 0.4; 0.6; 0.9]

x = 4×1

0.5000 0.4000 0.6000 0.9000

[y,z] = sort(x,'descend')

y = 4×1

0.9000 0.6000 0.5000 0.4000

z = 4×1

4 3 1 2

[YAHYA AL-MOLIKI]

Thak you

Answer 2

[Arif Hoq]

x=[0.5; 0.4; 0.6; 0.9];
y=sort(x,'descend');
[Lia,Locb] = ismember(y,x);
z=Locb'

z = 1×4

4 3 1 2

% if want as a column vector

out=Locb(:)

out = 4×1

4 3 1 2

[YAHYA AL-MOLIKI]

Thank you