DidierDeshommes

Didier

Email: MailTo(dfdeshom AT SPAMFREE gmail DOT com)

SAGE-related projects

Multiplication algorithm

A (slightly) faster multiplication algorithm of univariate polynomnials over R. Currently, this is known as _mul_fateman() in rings/polynomial_element.py but needs to be faster, probably through PARI or PyrexDELTA: I've finally started working on this. See my ext/polynomial_pyx.pyx for a preview. As predicted, the speedup is nice. Only integers are handled for now.

DELTA: Martin suggested working directly from ntl_ZZ integers. Will have to investigate this.

DELTA: The implementation is done (07/06), as expected, it's slower over ZZ and QQ but faster over RR

DELTA: Correcting bug: handling of polys with big (10^6) coefficients. It's really slow for bigger rational coefficients

RealLib inclusion

• RealLib3 as an alternate source for computing real numbers.

• RealLib vs MPFR:

  • RealLib tries to compute numbers exactly, instead of rounding to

    • the nearest valid floating-point number.
  • Computations take more time, but are exact

  • RealLib may not round correctly (not according to IEEE 754)

• RealLib should not be a replacementto MPFR. MPFR has its uses and is

  • faster than RealLib3

• The wrapper for it has already been written (modeled after MPFR), we're just
  • waiting for the developper to add a GPL-compatible license to it.

DELTA: Some AMD64 compilation problems prevent me from working on this on the sage server.

• Builds nicely on x86 though.

DELAT: Thanks to Dr Lambov, this now compiles on 386 and AMD64. I've built a new version and posted patches.

Tweaking Hermes

Logging of sessions using mathml through hermes:

• Improve, add fonts to hermes
• The final goal is to be able to reproduce the entire documentation
  • in mathmml format. This is currently possible if you hack up some missing

    fonts and avoid to generate the table of contents. Quite a pain I'll post a link to the generated doc

Logging of pictures in dvi and mathml logger.

• Possible, but slightly tricky (how do you include a jpeg file in a DVI file
  • without converting it to an EPS file?).

DELTA: Currently doesn't compile on AMD64!

DELTA: Actually, it does after some modifications by Martin.

cimport-ing RealNumber types

Kinda annoying and unituitive (from a user's POV) of why you cannot do "cimport mpfr"

• I think this should be quick and painless to do...

DELTA: done, submitted as a patch for possible inclusion

IDEAS/Wishlist for SAGE

easily generate random polynomials over rings

* Just a shorthand fucntions that doesnt male me write this every time: sage: x = ZZ['x'].gen() ; h = sum([randint(10^5,106)*x^i for i in range(1000)]); * should look like:

• randpoly(R,min_coef=0,max_coef,max_degree,dense=True)
• Better yet, we should be able to specify the level of sparsity

* See "Random elements" on SAGE projects page

doctest status script

Does each method have an example? Instead of checking by hand a handy script could be used

Automatic build+testing

* sage -br is nice, but how about an option to also run tests on any file that is being rebuilt?

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