[Xapian-discuss] Bug: scriptindex - xapian-omega 0.9.99_svn8484

[Olly Betts]

On Fri, May 11, 2007 at 03:23:42PM -0700, Kevin Duraj wrote:
> This is my result when I sort by value and relevance.
> Xapian treating the result as string and sorting it accordingly ....

That's the documented behaviour - "Sorting is with a string compare"
as it says in the API documentation for the sort_key parameter of
set_sort_by_value_then_relevance() (and set_sort_by_value() and
set_sort_by_relevance_then_value()):

    void Xapian::Enquire::set_sort_by_value_then_relevance(
            Xapian::valueno sort_key,
            bool ascending = true
            )       
        
    Set the sorting to be by value, then by relevance for documents with
    the same value.

    Parameters:

        sort_key        value number to reorder on. Sorting is with a
                string compare. If ascending is true (the default)
                higher is better; if ascending is false, lower is better.

        ascending       If true, documents values which sort higher by
                string compare are better. If false, the sort order is
                reversed. (default true)

See http://www.xapian.org/docs/apidoc/html/classXapian_1_1Enquire.html

> Value:9.48910782703839
> Value:9.48903215258983
> Value:9.48888078651068
> Value:9.48880509487835
> Value:44.7864142310669
> Value:42.1408884722407
> Value:41.0120506955037

If you want numbers to sort numerically, you'll either need to zero (or
space) pad them, or prefix the length of the integer part (say prefix
A for 1 up to Z for 26).  For example:

Value                   Zero Pad                   Length Prefix

0                       00000000                   A0
9.48910782703839        00000009.48910782703839    A9.48910782703839
12                      00000012                   B12
44.7864142310669        00000044.7864142310669     B44.7864142310669
997.4                   00000997.4                 C997.4
1000000                 01000000                   G1000000

Cheers,
    Olly