VSIPL 1.6 RTF Avatar
  1. OMG Issue

VSIPL16 — Meaning of vsip_symmetry enum values inconsistent

  • Key: VSIPL16-17
  • Legacy Issue Number: 18212
  • Status: open  
  • Source: dpdx.net ( Brooks Moses)
  • Summary:

    The vsip_symmetry enumerator is used in a number of places, and in
    general the VSIP_SYM_EVEN_LEN_* values are defined as "(Even) Symmetric,



    However, in the text there are sporadic mentions that imply that
    symmetric here really means conjugate-symmetric; for instance, see the
    bottom of page 567 ("The filter kernel can be even (conjugate) symmetric
    or non-symmetric.") and the definition of the "kernel" argument to
    vsip_*fir_create on page 612. This needs to be much more clearly and
    consistently stated.

    Regardless of whether the kernel is defined as symmetric or
    conjugate-symmetric, the method for constructing the complete kernel
    from the input in the symmetric cases is not defined. Is the input the
    first half of the kernel, or the second half? Is the first half
    conjugated, or the second half? This needs to be clearly specified.

  • Reported: VSIPL++ 1.2 — Tue, 23 Oct 2012 04:00 GMT
  • Updated: Fri, 6 Mar 2015 20:57 GMT