|
Pedro Fortuny Ayuso on Thu, 02 Mar 2017 10:01:02 +0100
|
[Date Prev] [Date Next] [Thread Prev] [Thread Next] [Date Index] [Thread Index]
|
Re: Mathematica "Reduce" function
|
- To: <pari-users@pari.math.u-bordeaux.fr>
- Subject: Re: Mathematica "Reduce" function
- From: Pedro Fortuny Ayuso <fortunypedro@uniovi.es>
- Date: Thu, 2 Mar 2017 10:00:48 +0100
- Authentication-results: pari.math.u-bordeaux.fr; dkim=none (message not signed) header.d=none;pari.math.u-bordeaux.fr; dmarc=none action=none header.from=uniovi.es;
- Delivery-date: Thu, 02 Mar 2017 10:01:02 +0100
- Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=unioviedo.onmicrosoft.com; s=selector1-uniovi-es; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version; bh=IbPkePhtAmoRnW4FVleBU2m5JvOfY7N/KpwXNaUGO9s=; b=CJhQzJjN3/zVuaIyawSGBmOaujZormwUsbVLpe3xBHVoMIWFzrRad5zmBUYyaDOwMbKcI5EgctAJDi9NAY10K/Nos260tJPqae61MKsVkV+sRo0GSQmtjovBhS5HdJjI/wiC6VU1fxa+4zLYzfMZ72hQujvlw6UqYMn60PUhAUk=
- In-reply-to: <20170301180155.GE23217@yellowpig>
- References: <20170301164507.GK1825@MBP-pfortuny.local> <20170301170514.GA23217@yellowpig> <20170301180155.GE23217@yellowpig>
- Spamdiagnosticmetadata: NSPM
- Spamdiagnosticoutput: 1:99
- User-agent: Mutt/1.5.20 (2009-06-14)
Thanks to all.
My specific problem is trying to solve equations like
6x^2 + 12y^2 +20z^2 = 0
over Z/(2^k)Z. That is, finding the points of that surface
over that ring.
Bill's reply of counting
length([[x,y,z]|x<-[0..2^k-1];y<-[0..2^k-1];z<-[0..2^k-1],6*x^2+12*y^2+20*z^2==0])
is the fastest but it ***looks like*** a lot slower than
Mathematica (but please notice I am working on a system
with pari/gp and my colleague on a different one with Mathematica,
so that it may have nothing to do with pari/Mathematica).
I know nothing about number theory, I just can guess what
'solving on the p-adics and then lifting' might mean but
am not quite ready to implement it.
Thanks again,
Pedro.
--
Pedro Fortuny Ayuso
http://pfortuny.net
EPIG, Campus de Viesques, Gijon
Dpto. de Matematicas
Universidad de Oviedo