An equivalent of the MS-Excel RANK function such that

> [32 12 22 69 46] in a column I get the result [3 1 2 5 4]. This is
> of course not the same as the indices returned from the sort function.

 >> x=[32 12 22 69 46]
x =
     32 12 22 69 46
 >> [y,ind]=sort(x)
y =
     12 22 32 46 69
ind =
      2 3 1 5 4

ind(j) = n means that the n-th entry of x
is the j-th lowest value.

You want to invert the map, to get a vector
ind1 with the property that ind1(n) = j
if and only if ind(j) = n.

This will do it:
 >> ind1=zeros(size(x));
 >> ind1(ind)=1:length(x)
ind1 =
      3 1 2 5 4

This will also do it, but I'm having a hard time
proving to myself why it works or if it works
in general:

 >> [y,ind1]=sort(ind)
y =
      1 2 3 4 5
ind1 =
      3 1 2 5 4