Re: Functions elllderiv and ellanalyticrank

[Bill Allombert <Bill.Allombert@math.u-bordeaux1.fr>]

On Fri, Dec 19, 2008 at 07:20:53PM +0100, Karim Belabas wrote:
> > 2) I think elllderiv should be renamed ellL1 for consistency with bnrL1
> > (and maybe add a flag so that both functions have the same semantic).
> > 
> > 7) Please document what is VSX in #define VSX 5.
> > (Or better remove VSX. One day someone will create a CPU called VSX and
> > gcc with define VSX. It already appened with k6 and sgi.)
> > 
> 
> Hi Bill, 
> 
>   thanks for looking at the patch and the detailed comments. I did look
> at it too, but was too lazy to explain every single change; hence the
> 6 "cleanup" commits yesterday and this morning [ 11462 to 11468 ]
> 
> The current svn version already incorporates all the above (and many more),
> except the second error message in 6). ( Which I believe is an
> impossible situation but had no time to check yet.)

It seems points 2) and 7) above were missed.

Also the DEBUG message should be improved to be more useful.

> There are only two items left from my initial TODO list about this
> patch:
> 
> A) It still uses far too much memory, so that the "small" curves with
> rank 7 (say) can't be handled with a PARI stack of 1GByte.
> 
> B) Once A) is no longer a problem (say, in about 40 minutes), check Tom
> Womack's table at
> 
>   http://www.warwick.ac.uk/staff/J.E.Cremona/womack.html
> 
> Many interesting curves with "largish but tolerable" conductor...

I just checked the first curves for each rank <=7, and it worked fine.
For the rank 7, and curve [0,1,0,-5945,583879], we get:

%3 = [7, 10410274.011880989226208667596394924308]
  ***   last result computed in 32mn, 22,973 ms.

Cheers,
Bill.