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Python EllipticCurve.rst_transform方法代码示例

本文整理汇总了Python中constructor.EllipticCurve.rst_transform方法的典型用法代码示例。如果您正苦于以下问题:Python EllipticCurve.rst_transform方法的具体用法?Python EllipticCurve.rst_transform怎么用?Python EllipticCurve.rst_transform使用的例子?那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在constructor.EllipticCurve的用法示例。


在下文中一共展示了EllipticCurve.rst_transform方法的1个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的Python代码示例。

示例1: _tate

# 需要导入模块: from constructor import EllipticCurve [as 别名]
# 或者: from constructor.EllipticCurve import rst_transform [as 别名]

#.........这里部分代码省略.........

            if val_disc == 0:
                ## Good reduction already
                cp = 1
                fp = 0
                KS = KodairaSymbol("I0")
                break #return

            # Otherwise, we change coordinates so that p | a3, a4, a6
            if p == 2:
                if pdiv(b2):
                    r = proot(a4, 2)
                    t = proot(((r + a2)*r + a4)*r + a6, 2)
                else:
                    temp = pinv(a1)
                    r = temp * a3
                    t = temp * (a4 + r*r)
            elif p == 3:
                if pdiv(b2):
                    r = proot(-b6, 3)
                else:
                    r = -pinv(b2) * b4
                t = a1 * r + a3
            else:
                if pdiv(c4):
                    r = -pinv(12) * b2
                else:
                    r = -pinv(12*c4) * (c6 + b2 * c4)
                t = -halfmodp * (a1 * r + a3)
            r = preduce(r)
            t = preduce(t)
            verbose("Before first transform C = %s"%C)
            verbose("[a1,a2,a3,a4,a6] = %s"%([a1, a2, a3, a4, a6]))
            C = C.rst_transform(r, 0, t)
            (a1, a2, a3, a4, a6) = C.a_invariants()
            (b2, b4, b6, b8) = C.b_invariants()
            if min([pval(a) for a in (a1, a2, a3, a4, a6) if a != 0]) < 0:
                raise RuntimeError("Non-integral model after first transform!")
            verbose("After first transform %s\n, [a1,a2,a3,a4,a6] = %s\n, valuations = %s"%([r, 0, t], [a1, a2, a3, a4, a6], [pval(a1), pval(a2), pval(a3), pval(a4), pval(a6)]), t, 2)
            if pval(a3) == 0:
                raise RuntimeError("p does not divide a3 after first transform!")
            if pval(a4) == 0:
                raise RuntimeError("p does not divide a4 after first transform!")
            if pval(a6) == 0:
                raise RuntimeError("p does not divide a6 after first transform!")

            # Now we test for Types In, II, III, IV
            # NB the c invariants never change.

            if not pdiv(c4):
                # Multiplicative reduction: Type In (n = val_disc)
                split = False
                if _pquadroots(1, a1, -a2):
                    cp = val_disc
                    split = True
                elif Integer(2).divides(val_disc):
                    cp = 2
                else:
                    cp = 1
                KS = KodairaSymbol("I%s"%val_disc)
                fp = 1
                break #return

            # Additive reduction

            if pval(a6) < 2:
开发者ID:amitjamadagni,项目名称:sage,代码行数:70,代码来源:ell_local_data.py


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