Re: [boost] Request to allow contribution to Boost.Multiprecision cpp_bin_float

Subject: Re: [boost] Request to allow contribution to Boost.Multiprecision cpp_bin_float
From: Jyotesh Choudhari (jyoteshrc_at_[hidden])
Date: 2013-08-20 06:09:54

Thanks for your replies.

>>> I would like to contribute to the development of Boost.Multiprecision

>>> cpp_bin_float library. Can I work on it? If yes, then how can I start?

>> Hi Jyotesh,

>> Paul Bristow, Chris Kormanyos and I have been discussing this off-list.
>> There is a prototype implementation in the sandbox under the
>> multiprecision.cpp_bin_float directory.? The current code is pretty much
>> complete, but under-tested.? The binary-decimal and decimal-binary
>> conversion routines used are also brain-dead and do not round correctly
(I
>> have a mostly working version that does this correctly on my hard drive,
but
>> it's not quite ready for commit yet).

> Yes. But remember, Jyotesh, John has taken a different direction
> than my original code in the sandbox. His implementation is in
> a different directory, and it's likely that we will stick with John's
> and leave my prototyping to rest.

May I know which directory is this?

>> So one of the things we need is for
>> folks to try this out and see what breaks (or rather to see what they can
>> break!).

> Such as try some simple math functions or to use it in
> conjunction with boost::math::constants for, say, computing
> a few hundred digits of pi or log(2).

OK. I will try these.

>> Some of the std lib function test cases in the sandbox also fail
>> currently as their error rates are too high.? Many are also much slower
than
>> say MPFR.? Chris, would have a better idea which most need working on.

> Always important are square root, sine, cosine, and log.

>> And finally, the implementation uses all integral arithmetic internally
(via
>> cpp_int), so one big improvement we need is for someone to write
Karatsuba
>> and FFT based multiplication routines for cpp_int (Karatsuba is probably
the
>> higher priority).? Oh and we have no docs yet.

> Yes, very important, as this is a huge limitation of cpp_dec_float ---
> at least for the digit hunters among us. :-)

I will implement Karatsuba algorithm and let you know when I am finished.

Thanks and Regards,
Jyotesh Choudhari

>> Anything there look like something you'd like to work on?
>> Thanks for the interest, John.

> Thanks for the interest.

> Sincerely, Chris.