I'm creating this page in an attempt to document what I learn about Bruce's polynomial regression implementation in Language-ID/scripts/seg2xml3.pl. Currently this code fails under Cygwin and 64-bit Linux, so the better I understand it the more likely I can fix it. --[[User:Josh|Josh]] 17:29, 28 June 2007 (MDT)

The implementation utilizes the [http://pdl.perl.org/ PDL] numerics library. Bruce is using the following includes:
:use strict;
:use Data::Dumper;
:use POSIX qw(ceil floor);
:use PDL ();
:use PDL::Ops ();
:use PDL::Fit::Polynomial ();

He notes in a comment:
:Use empty list () after PDL imports to avoid having it pollute our namespace with unwanted symbols, such as a ceil and floor that clobber (and are incompatible with) the ones imported from POSIX. See "perldoc -f use" for details on the "use ... ()" syntax.
:PDL's importer doesn't behave normally; it imports symbols even when you give an explicit list a la "use PDL qw(pdl)".

Question: Why use the POSIX ceil and floor instead of the PDL::Math ceil and floor?

[[Category:Spoken Language ID]]