当前位置: 首页>>代码示例>>Python>>正文


Python Integer.factor方法代码示例

本文整理汇总了Python中sage.rings.all.Integer.factor方法的典型用法代码示例。如果您正苦于以下问题:Python Integer.factor方法的具体用法?Python Integer.factor怎么用?Python Integer.factor使用的例子?那么恭喜您, 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sage.rings.all.Integer的用法示例。


在下文中一共展示了Integer.factor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: solve_mod

# 需要导入模块: from sage.rings.all import Integer [as 别名]
# 或者: from sage.rings.all.Integer import factor [as 别名]
def solve_mod(eqns, modulus, solution_dict = False):
    r"""
    Return all solutions to an equation or list of equations modulo the
    given integer modulus. Each equation must involve only polynomials
    in 1 or many variables.

    By default the solutions are returned as `n`-tuples, where `n`
    is the number of variables appearing anywhere in the given
    equations. The variables are in alphabetical order.

    INPUT:


    -  ``eqns`` - equation or list of equations

    -  ``modulus`` - an integer

    -  ``solution_dict`` - bool (default: False); if True or non-zero,
       return a list of dictionaries containing the solutions. If there
       are no solutions, return an empty list (rather than a list containing
       an empty dictionary). Likewise, if there's only a single solution,
       return a list containing one dictionary with that solution.


    EXAMPLES::

        sage: var('x,y')
        (x, y)
        sage: solve_mod([x^2 + 2 == x, x^2 + y == y^2], 14)
        [(4, 2), (4, 6), (4, 9), (4, 13)]
        sage: solve_mod([x^2 == 1, 4*x  == 11], 15)
        [(14,)]

    Fermat's equation modulo 3 with exponent 5::

        sage: var('x,y,z')
        (x, y, z)
        sage: solve_mod([x^5 + y^5 == z^5], 3)
        [(0, 0, 0), (0, 1, 1), (0, 2, 2), (1, 0, 1), (1, 1, 2), (1, 2, 0), (2, 0, 2), (2, 1, 0), (2, 2, 1)]

    We can solve with respect to a bigger modulus if it consists only of small prime factors::

        sage: [d] = solve_mod([5*x + y == 3, 2*x - 3*y == 9], 3*5*7*11*19*23*29, solution_dict = True)
        sage: d[x]
        12915279
        sage: d[y]
        8610183

    For cases where there are relatively few solutions and the prime
    factors are small, this can be efficient even if the modulus itself
    is large::

        sage: sorted(solve_mod([x^2 == 41], 10^20))
        [(4538602480526452429,), (11445932736758703821,), (38554067263241296179,),
        (45461397519473547571,), (54538602480526452429,), (61445932736758703821,),
        (88554067263241296179,), (95461397519473547571,)]

    We solve a simple equation modulo 2::

        sage: x,y = var('x,y')
        sage: solve_mod([x == y], 2)
        [(0, 0), (1, 1)]

    .. warning::

       The current implementation splits the modulus into prime
       powers, then naively enumerates all possible solutions
       (starting modulo primes and then working up through prime
       powers), and finally combines the solution using the Chinese
       Remainder Theorem.  The interface is good, but the algorithm is
       very inefficient if the modulus has some larger prime factors! Sage
       *does* have the ability to do something much faster in certain
       cases at least by using Groebner basis, linear algebra
       techniques, etc. But for a lot of toy problems this function as
       is might be useful. At least it establishes an interface.


    TESTS:

    Make sure that we short-circuit in at least some cases::

        sage: solve_mod([2*x==1], 2*next_prime(10^50))
        []

    Try multi-equation cases::

        sage: x, y, z = var("x y z")
        sage: solve_mod([2*x^2 + x*y, -x*y+2*y^2+x-2*y, -2*x^2+2*x*y-y^2-x-y], 12)
        [(0, 0), (4, 4), (0, 3), (4, 7)]
        sage: eqs = [-y^2+z^2, -x^2+y^2-3*z^2-z-1, -y*z-z^2-x-y+2, -x^2-12*z^2-y+z]
        sage: solve_mod(eqs, 11)
        [(8, 5, 6)]

    Confirm that modulus 1 now behaves as it should::

        sage: x, y = var("x y")
        sage: solve_mod([x==1], 1)
        [(0,)]
        sage: solve_mod([2*x^2+x*y, -x*y+2*y^2+x-2*y, -2*x^2+2*x*y-y^2-x-y], 1)
        [(0, 0)]
#.........这里部分代码省略.........
开发者ID:novoselt,项目名称:sage,代码行数:103,代码来源:relation.py


注:本文中的sage.rings.all.Integer.factor方法示例由纯净天空整理自Github/MSDocs等开源代码及文档管理平台,相关代码片段筛选自各路编程大神贡献的开源项目,源码版权归原作者所有,传播和使用请参考对应项目的License;未经允许,请勿转载。