本文整理汇总了Python中sage.rings.all.ZZ.abs方法的典型用法代码示例。如果您正苦于以下问题：Python ZZ.abs方法的具体用法？Python ZZ.abs怎么用？Python ZZ.abs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类sage.rings.all.ZZ的用法示例。
在下文中一共展示了ZZ.abs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: _eval_
# 需要导入模块: from sage.rings.all import ZZ [as 别名]
# 或者: from sage.rings.all.ZZ import abs [as 别名]
def _eval_(self, n, x):
"""
The :meth:`_eval_()` method decides which evaluation suits best
for the given input, and returns a proper value.
EXAMPLES::
sage: var('n,x')
(n, x)
sage: chebyshev_T(5,x)
16*x^5 - 20*x^3 + 5*x
sage: chebyshev_T(64, x)
2*(2*(2*(2*(2*(2*x^2 - 1)^2 - 1)^2 - 1)^2 - 1)^2 - 1)^2 - 1
sage: chebyshev_T(n,-1)
(-1)^n
sage: chebyshev_T(-7,x)
64*x^7 - 112*x^5 + 56*x^3 - 7*x
sage: chebyshev_T(3/2,x)
chebyshev_T(3/2, x)
sage: R.<t> = QQ[]
sage: chebyshev_T(2,t)
2*t^2 - 1
sage: chebyshev_U(2,t)
4*t^2 - 1
sage: parent(chebyshev_T(4, RIF(5)))
Real Interval Field with 53 bits of precision
sage: RR2 = RealField(5)
sage: chebyshev_T(100000,RR2(2))
8.9e57180
sage: chebyshev_T(5,Qp(3)(2))
2 + 3^2 + 3^3 + 3^4 + 3^5 + O(3^20)
sage: chebyshev_T(100001/2, 2)
doctest:...: RuntimeWarning: mpmath failed, keeping expression unevaluated
chebyshev_T(100001/2, 2)
sage: chebyshev_U._eval_(1.5, Mod(8,9)) is None
True
"""
# n is an integer => evaluate algebraically (as polynomial)
if n in ZZ:
n = ZZ(n)
# Expanded symbolic expression only for small values of n
if is_Expression(x) and n.abs() < 32:
return self.eval_formula(n, x)
return self.eval_algebraic(n, x)
if is_Expression(x) or is_Expression(n):
# Check for known identities
try:
return self._eval_special_values_(n, x)
except ValueError:
# Don't evaluate => keep symbolic
return None
# n is not an integer and neither n nor x is symbolic.
# We assume n and x are real/complex and evaluate numerically
try:
import sage.libs.mpmath.all as mpmath
return self._evalf_(n, x)
except mpmath.NoConvergence:
warnings.warn("mpmath failed, keeping expression unevaluated", RuntimeWarning)
return None
except Exception:
# Numerical evaluation failed => keep symbolic
return None