## digitalmars.D.announce - Mister Math is wanted!

"Ilya Yaroshenko" <ilyayaroshenko gmail.com> writes:
```Hello all!

Python's fsum is ready for D :
https://github.com/D-Programming-Language/phobos/pull/2991

Destroy!
```
Feb 26 2015
Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:
```On 2/26/15 5:34 AM, Ilya Yaroshenko wrote:
Hello all!

Python's fsum is ready for D :
https://github.com/D-Programming-Language/phobos/pull/2991

Destroy!

Unfortunate overlap in functionality is unfortunate.

\$ git grep -i kahan
std/algorithm/iteration.d:\$(D sum) uses the \$(WEB
en.wikipedia.org/wiki/Kahan_summation,
std/algorithm/iteration.d:Kahan summation) algorithm.)
std/algorithm/iteration.d:            return sumKahan!E(seed, r);
std/algorithm/iteration.d:// Kahan algo
http://en.wikipedia.org/wiki/Kahan_summation_algorithm
std/algorithm/iteration.d:private auto sumKahan(Result, R)(Result
result, R r)
\$ _

Andrei
```
Feb 26 2015
"Ilya Yaroshenko" <ilyayaroshenko gmail.com> writes:
``` Unfortunate overlap in functionality is unfortunate.

\$ git grep -i kahan
std/algorithm/iteration.d:\$(D sum) uses the \$(WEB
en.wikipedia.org/wiki/Kahan_summation,
std/algorithm/iteration.d:Kahan summation) algorithm.)
std/algorithm/iteration.d:            return sumKahan!E(seed,
r);
std/algorithm/iteration.d:// Kahan algo
http://en.wikipedia.org/wiki/Kahan_summation_algorithm
std/algorithm/iteration.d:private auto sumKahan(Result,
R)(Result result, R r)
\$ _

Andrei

Would one of the following solutions be fortunate ?

I. Use alias of fsum!(Summation. Appropriate) for floating
version of std.algorithm.sum.

Appropriate algorithm performs D Pairwise summation for
random access ranges.
Otherwise performs D KBN summation of floating point and
complex numbers and
Kahan summation of user defined types.

or

II. Move this submodule to std.algorithm.iteration.

or

III. Remove Kahan (including KBN and KB2) and Pairwise algorithms
from fsum, and use only Precise algorithm for std.numeric.
```
Feb 27 2015
"Ilya Yaroshenko" <ilyayaroshenko gmail.com> writes:
```On Friday, 27 February 2015 at 09:27:49 UTC, Ilya Yaroshenko
wrote:
Unfortunate overlap in functionality is unfortunate.

\$ git grep -i kahan
std/algorithm/iteration.d:\$(D sum) uses the \$(WEB
en.wikipedia.org/wiki/Kahan_summation,
std/algorithm/iteration.d:Kahan summation) algorithm.)
std/algorithm/iteration.d:            return sumKahan!E(seed,
r);
std/algorithm/iteration.d:// Kahan algo
http://en.wikipedia.org/wiki/Kahan_summation_algorithm
std/algorithm/iteration.d:private auto sumKahan(Result,
R)(Result result, R r)
\$ _

Andrei

Would one of the following solutions be fortunate ?

I. Use alias of fsum!(Summation. Appropriate) for floating
version of std.algorithm.sum.

Appropriate algorithm performs D Pairwise summation for
random access ranges.
Otherwise performs D KBN summation of floating point and
complex numbers and
Kahan summation of user defined types.

or

II. Move this submodule to std.algorithm.iteration.

or

III. Remove Kahan (including KBN and KB2) and Pairwise
algorithms from fsum, and use only Precise algorithm for
std.numeric.

Probably, I have found good solution. Summator struct can be
represented in std.numeric and std.algorithm.sum can be extended
by the new functionality. So there will be no overlap in
functionality.
```
Feb 27 2015