psVectorSortIndex algorithm

[Paul Price]

The algorithm adopted for psVectorSortIndex (sort the vector and then find out
where my data ends up) is by no means optimal. The natural algorithm is:

1. Generate a vector of indices (0,1,2,3,4,5,...,N)
2. Make a comparison function that, given two indices, compares the

corresponding values of the input vector (e.g., given 2 and 5, it compares
myVector->data.F32[2] and myVector->data.F32[5]).

3. Sort the vector of indices (#1) using qsort(), employing the comparison

function (#2)

4. Return the sorted vector of indices.

[robert.desonia@…]

It is not as simple as that, as there is no way to pass the vector into the
compare function. One could create a global variable set to the vector
currently being sorted, but there is thread-safety problems associated with that
approach.

Let me think about a better way to skin this one for awhile.

[robert.desonia@…]

rewrote the function by sticking the data in an array of structs that holds the
data along with the index then usinf qsort to sort the structs. This ensures
all the indices are included in the output, even in the case of duplicate values.

-rdd

[Paul Price]

Bug has been resolved.... closing.

[Paul Price]

Bugs have been fixed... closing.