Bill Allombert on Sat, 09 Aug 2014 22:53:10 +0200

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Re: New ellL1 implementation by Pascal Molin

On Wed, Jun 25, 2014 at 02:24:09PM +0200, Bill Allombert wrote:
> On Sun, Jun 22, 2014 at 12:21:25PM +0200, Bill Allombert wrote:
> > Dear PARI developers,
> > 
> > I have merged Pascal Molin code for computing ellL1 and ellanalyticrank.
> > The new code is much faster than the old one for derivatives.
> > For the value of L itself, it is slightly slower, but only because the
> > older code used unproven (and sometimes wrong) bounds for the summation.
> > 
> > This makes ellheegner faster when the height of the point is large.
> I have commited a second patch that adds an alternative summation strategy
> suggested by Pascal. ellL1 will choose the strategy that requires the less
> amount of memory.

I have commited a third patch that implement Brent and Kung summation for
ellheegner too, when the naive height of the point is > 1900*log(2).
This is significantly faster than the previous summation strategy.

The bound 1900 is not very sharp. It is not very easy to tune this.