Re: [Boost-bugs] [Boost C++ Libraries] #7549: uBLAS banded storage does not match common BLAS layout (from netlib)

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #7549: uBLAS banded storage does not match common BLAS layout (from netlib)
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2012-10-21 20:54:35

#7549: uBLAS banded storage does not match common BLAS layout (from netlib)
-------------------------------+--------------------------------------------
  Reporter:  guwi17            |       Owner:  guwi17                    
      Type:  Bugs              |      Status:  new                       
 Milestone:  To Be Determined  |   Component:  uBLAS                     
   Version:  Boost 1.52.0      |    Severity:  Problem                   
Resolution:                    |    Keywords:  ublas banded matrix layout
-------------------------------+--------------------------------------------

Comment (by guwi17):

 The responsible code is in `banded.hpp` around line 163. The mapping from
 index (i,j) to storage location is
 {{{
    const size_type k = j;
    const size_type l = upper_ + i - j;
    if (k < size2_ && l < lower_ + 1 + upper_)
    return data () [layout_type::element (k, size2_, l, lower_ + 1 +
 upper_)];
 }}}
 where `layout_type` is either `basic_row_major` or `basic_column_major`
 (from `functional.hpp`)
 We should extract the existing mapping logic to a functor (similar to
 triangular types `basic_lower` and `basic_upper`) and introduce a new
 template argument.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/7549#comment:3>
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