sort and assign ranking

Hi I need to sort a vector and assign a ranking for the corresponding sorting order. I'm using sort function [sortedValue_X , X_Ranked] = sort(X,'descend'); but the problem is it assignes different ranks for the same values (zeros). ie x = [ 13 15 5 5 0 0 0 1 0 3] and i want zeros to take the same last rank which is 6 and fives needs to share the 3rd rank etc.. any suggestions?

Answer 1

[Image Analyst]

You can use the third return argument of unique(): Try this:

X = [ 13 15 5 5 0 0 0 1 0 3] 
[sortedValue_X , X_Ranked] = sort(X,'descend')
[uniqueValues, ia, ic]=unique(sortedValue_X)
X_Ranked = max(ic)-ic+1 % <- there's your answer!

In command window:

X_Ranked =
     1     2     3     3     4     5     6     6     6     6

[Gokturk]

Hi, I do have a small but an important issue, X_ranked vector gives sorted values, points should be in their places, X_Ranked should be [1 2 3 3 6 6 6 5 6 4] can you pls help on this? many thanks

Answer 2

[TjeerdB]

X = [13 15 5 5 0 0 0 1 0 3];
[temp,X_ranked]  = ismember(X,unique(X))

In command window:

X_ranked =

       5     6     4     4     1     1     1     2     1     3