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List Info Thread: dotc and dotu in glas
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dotc and dotu in glas |
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List Info Thread: dotc and dotu in glas
[1-3]
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lists.boost.org
>>>
the MTL
would suggest that
it is dotu. Possibly the latter option was just too
straightforward to be
avoided in first place but retaining option 1 could be well
worth a
confirmation. Was that Matthias meant?
>
>
> Matthias Troyer wrote:
>
> >I want to strongly support Andrew's statement. If
one wants only one
> >dot product then the proper inner product for a
complex Hilbert space
> >needs to be chosen.
> >
> >Matthias
> >
> >On May 1, 2006, at 10:59 AM, Andrew Lumsdaine
wrote:
> >
> >
> >
> >>Both are needed.
> >>
> >>In the Iterative Template Library, both are
required in order for the
> >>solvers to work properly with complex vectors.
> >>
> >>Mathematically, dotc() is a proper inner
product for a complex Hilbert
> >>space, dotu() is not. If a single dot()
function is going to be used
> >>for inner product, mathematically it must be
equivalent to dotc().
> >>
> >>Use cases are very important when creating
interfaces for a generic
> >>library. I would suggest taking a look at ITL
and IETL to see how
> >>generic linear concepts at this level of
abstraction are used.
> >>
> >>Toon Knapen wrote:
> >>
> >>
> >>>I was wondering if we need an equivalent
for both the dotc and
> >>>dotu of
> >>>BLAS in glas? I suggest to only have _one_
dot function (which is
> >>>equivalent to the dot in blas for vectors
of reals and which
> >>>corresponds
> >>>to dotu for vectors of complex values). To
perform the equivalent of
> >>>dotc one could then write dot(conj(x),y).
This is IMHO clearer and
> >>>the
> >>>expression-template mechanism will avoid
that this compound
> >>>expression
> >>>will induce a performance penalty.
> >>>
> >>>I just added an equivalent to dotc but I
plan to add the solution as
> >>>described above, benchmark both and than
remove the dotc equivalent
> >>>afterwards (supposing the benchmark will
not show any performance
> >>>differences of both approaches).
> >>>
> >>>toon
> >>>
> >>>
>
>>>_______________________________________________
> >>>glas mailing list
> >>>glas