How to sort a vector according to another vector?

I am trying to write a code that will do thr following:

Input:

R=[a b c d]'; ranks=[1 2 3 1];

a has rank 1; b has rank 2;

c has rank 3; and d has rank 1;

I want to re-arrange R st that those elements whose ranks 1 are listed first followed by those who ranks 2 and so on.

So the output be:

R=[a d b c]'

This is a special case in other cases the vectors R and ranks will be very huge so I am trying to find a code that is efficient

Thank you

Answer 1

[dpb]

R=['a':'d'].';  % So can identify elements of R
% the engine
[~,ix]=sort(ranks);
% the result...
>> R(ix)
ans =
  4×1 char array
    'a'
    'd'
    'b'
    'c'
 >>

The elements of R will have to be single values to be stored in an array or R would need be a cell array to hold other objects.