bug: broken sign functions

The sign function maps zero to zero, cf.
http://en.wikipedia.org/wiki/Sign_function

The Lush sign functions yield something else (they are not
only wrong, but even inconsistent):

? (sgn 0)
= 1
? (libload "libidx/idx-double")
  [idx-double.lsh]
  [idx-macros.lsh]
= "/n/toaster/u/juenglin/psu-lush/lsh/libidx/idx-double.lsh"
? (let ((s [0 0 0])) (idx-d1sign [-2 0 2] s) s)
= [d -1.00 -1.00  1.00]
?

Is there any code (in the libraries) that would break with correct
sign functions?

Ralf



-------------------------------------------------------
SF.Net email is Sponsored by the Better Software Conference & EXPO
September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices
Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA
Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf