Re: [sage-support] integral points on ellipitc curves

2018-06-28 Thread grafix
Is any possibility to find on MAGMA of integral points on elliptic curve such type where coefficient by x^3 isn't equal 1 e.q.: A := AffineSpace(Rationals(),2); C := Curve(y^2-4*x^3+7*x+3); IntegralPoints(C); When I execute e.g. IntegralQuarticPoints([0, 4, 0, -7, -3]); output of Magma is: ) In

Re: [sage-support] integral points on ellipitc curves

2016-12-15 Thread John Cremona
A patch is up for review now at https://trac.sagemath.org/ticket/22063 On 15 December 2016 at 17:02, John Cremona wrote: > Without going so far as to use interval arithmetic (which leads to at > least one annoying problem: the RealIntervalField in Sage has no >

Re: [sage-support] integral points on ellipitc curves

2016-12-15 Thread John Cremona
Without going so far as to use interval arithmetic (which leads to at least one annoying problem: the RealIntervalField in Sage has no is_square() methods which is enough to make it hard to work with as far as creating points on elliptic curves is concerned) I came up with a better solution. I

Re: [sage-support] integral points on ellipitc curves

2016-12-15 Thread John Cremona
On 15 December 2016 at 14:52, wrote: > @John : Good point. The change in precision, at least seems to fix the > previous problems (at least in the specific examples). > I suppose, this is the precision that is used to bound the coefficients of > the linear form of elliptic

Re: [sage-support] integral points on ellipitc curves

2016-12-15 Thread drazioti
@John : Good point. The change in precision, at least seems to fix the previous problems (at least in the specific examples). I suppose, this is the precision that is used to bound the coefficients of the linear form of elliptic logarithms (?) If this is the case, and I remember right, this

Re: [sage-support] integral points on ellipitc curves

2016-12-15 Thread William Stein
On Thu, Dec 15, 2016 at 4:51 AM, Dima Pasechnik wrote: > > > On Thursday, December 15, 2016 at 12:23:15 PM UTC, John Cremona wrote: >> >> I just confirmed that if I change RealField(100) to RealField(200) in >> one place (line 6975 of ell_rational_field.py) then both the points

Re: [sage-support] integral points on ellipitc curves

2016-12-15 Thread Dima Pasechnik
On Thursday, December 15, 2016 at 12:23:15 PM UTC, John Cremona wrote: > > I just confirmed that if I change RealField(100) to RealField(200) in > one place (line 6975 of ell_rational_field.py) then both the points > Costas missed are found, so I was right that this is a stupid problem > of

Re: [sage-support] integral points on ellipitc curves

2016-12-15 Thread John Cremona
I just confirmed that if I change RealField(100) to RealField(200) in one place (line 6975 of ell_rational_field.py) then both the points Costas missed are found, so I was right that this is a stupid problem of precision rather than something more complicated. I can easily make a patch to make

Re: [sage-support] integral points on ellipitc curves

2016-12-15 Thread John Cremona
On 14 December 2016 at 21:34, wrote: > Thank you both for the answers, > > I found another problematic example > > sage:E1=EllipticCurve([0,0,0,37,18]);E1;S=E1.integral_points();S; > Elliptic Curve defined by y^2 = x^3 + 37*x + 18 > over Rational Field > [(2 : 10 : 1), (126 :

Re: [sage-support] integral points on ellipitc curves

2016-12-14 Thread drazioti
Thank you both for the answers, I found another problematic example sage:E1=EllipticCurve([0,0,0,37,18]);E1;S=E1.integral_points();S; Elliptic Curve defined by y^2 = x^3 + 37*x + 18 over Rational Field [(2 : 10 : 1), (126 : 1416 : 1)] and R = E1(64039202,512470496030);M=E1(2,10 );3*M==R

Re: [sage-support] integral points on ellipitc curves

2016-12-14 Thread Nils Bruin
On Wednesday, December 14, 2016 at 12:09:36 PM UTC-8, John Cremona wrote: > > > Thanks for the bug report. As Nils pointed out there are known bugs > in the integral point code which cause solutions to be missed. Just to make clear: I wasn't taking a jibe at sage/or John on this, and I wasn't

Re: [sage-support] integral points on ellipitc curves

2016-12-14 Thread John Cremona
Dear Costas, Thanks for the bug report. As Nils pointed out there are known bugs in the integral point code which cause solutions to be missed. A lot of work has been spent on improving this, in part by me, and the main reason the fixes have not yet been approved and merged is that I still had

[sage-support] integral points on ellipitc curves

2016-12-14 Thread drazioti
Hi all, I came across the following example... sage: E1=EllipticCurve([0,0,0,49,-64]);E1;S=E1.integral_points();S; Elliptic Curve defined by y^2 = x^3 + 49*x - 64 over Rational Field [(4 : 14 : 1), (464 : 9996 : 1)] but the following integer point Q belongs also to the curve