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Type inconsistency in rational points on elliptic curves #4820

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JohnCremona opened this issue Dec 17, 2008 · 4 comments
Closed

Type inconsistency in rational points on elliptic curves #4820

JohnCremona opened this issue Dec 17, 2008 · 4 comments
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@williamstein
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c: elliptic curves c: number theory p: minor / 4 t: bug
Milestone
sage-3.3

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@JohnCremona
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Points on elliptic curves over Q which are not [0:1:0] have their last coordinate =1 but sometimes this is an int (not even an Integer) which breaks some code:

sage: E=EllipticCurve('37a1')
sage: [type(c) for c in E(0)]

[<type 'sage.rings.rational.Rational'>,
 <type 'sage.rings.rational.Rational'>,
 <type 'sage.rings.rational.Rational'>]
sage: [type(c) for c in E.gen(0)]

[<type 'sage.rings.rational.Rational'>,
 <type 'sage.rings.rational.Rational'>,
 <type 'sage.rings.rational.Rational'>]
sage: [type(c) for c in 2*E.gen(0)]

[<type 'sage.rings.rational.Rational'>,
 <type 'sage.rings.rational.Rational'>,
 <type 'int'>]

I am tracking this down and will post a patch soon.

Component: number theory

Issue created by migration from https://trac.sagemath.org/ticket/4820
@JohnCremona JohnCremona added this to the sage-3.4.1 milestone Dec 17, 2008
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comment:1

Attachment: trac-4820.patch.gz

@ncalexan
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Mannequin

ncalexan mannequin commented Jan 21, 2009

comment:2

Looks fine by me. I checked that (0 : 1 : 0) over a non-standard ring had the correct types.

@sagetrac-mabshoff
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sagetrac-mabshoff mannequin commented Jan 23, 2009

comment:3

Merged in Sage 3.3.alpha1

Cheers,

Michael

@sagetrac-mabshoff sagetrac-mabshoff mannequin assigned sagetrac-mabshoff and unassigned williamstein Jan 23, 2009
@sagetrac-mabshoff sagetrac-mabshoff mannequin modified the milestones: sage-3.4.1, sage-3.3 Jan 23, 2009
@sagetrac-mabshoff sagetrac-mabshoff mannequin assigned williamstein and unassigned sagetrac-mabshoff Jan 23, 2009
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sagetrac-mabshoff mannequin commented Jan 23, 2009

comment:5

Merged in Sage 3.3.alpha1

Cheers,

Michael

@sagetrac-mabshoff sagetrac-mabshoff mannequin closed this as completed Jan 23, 2009
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c: elliptic curves c: number theory p: minor / 4 t: bug
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