EulerCharacteristic
EulerCharacteristic[poly]
给出 poly 的欧拉示性数.
更多信息
- EulerCharacteristic 亦成为欧拉数或 Euler–Poincaré 示性数.
- EulerCharacteristic 是一个描述多面体形状的拓扑不变量,不考虑它弯曲的方式.
- 多面体的欧拉示性数
由
给出,其中
是顶点数,
为边数,
为面数. - 有
个洞和
个巷道的多面体满足
. - 网格区域的欧拉示性数由 χ=
(-1)nMeshCellCount[poly,n] 给出.
范例
打开所有单元 关闭所有单元基本范例 (1)
𝒫 = Polyhedron[{{-Sqrt[1 + 2/Sqrt[5]], 0, Root[1 - 20*#1^2 + 80*#1^4 & , 3, 0]},
{Sqrt[1 + 2/Sqrt[5]], 0, Root[1 - 20*#1^2 + 80*#1^4 & , 2, 0]},
{Root[1 - 20*#1^2 + 80*#1^4 & , 1, 0], (-3 - Sqrt[5])/4, Root[1 - 20*#1^2 + 80*#1^4 & , 3, 0]},
{R ...
{{15, 10, 9, 14, 1}, {2, 6, 12, 11, 5}, {5, 11, 7, 3, 19}, {11, 12, 8, 16, 7}, {12, 6, 20, 4, 8},
{6, 2, 13, 18, 20}, {2, 5, 19, 17, 13}, {4, 20, 18, 10, 15}, {18, 13, 17, 9, 10},
{17, 19, 3, 14, 9}, {3, 7, 16, 1, 14}, {16, 8, 4, 15, 1}}];EulerCharacteristic[𝒫]Region[𝒫]范围 (4)
EulerCharacteristic 适用于多面体:
𝒫 = Polyhedron[{{0, 0, 0}, {1, 0, 0}, {0, 1, 0}, {0, 0, 1}}, {{1, 2, 3}, {1, 2, 4}, {2, 3, 4},
{1, 3, 4}}];EulerCharacteristic[𝒫]Region[𝒫]EulerCharacteristic[Tetrahedron[]]EulerCharacteristic[Hexahedron[]]Polyhedron[{{0, 0, 0}, {0, 3, 0}, {3, 3, 0}, {3, 0, 0}, {0, 0, 3}, {0, 3, 3}, {3, 3, 3}, {3, 0, 3}, {1, 1, 1}, {1, 2, 1}, {2, 2, 1}, {2, 1, 1}, {1, 1, 2}, {1, 2, 2}, {2, 2, 2}, {2, 1, 2}}, {{{2, 3, 4, 1}, {1, 4, 8, 5}, {4, 3, 7, 8}, {3, 2, 6, 7}, {2, 1, 5, 6}, {5, 8, 7, 6}} -> {{{10, 11, 12, 9}, {9, 12, 16, 13}, {12, 11, 15, 16}, {11, 10, 14, 15}, {10, 9, 13, 14}, {13, 16, 15, 14}}}}];EulerCharacteristic[%]Polyhedron[{{0, 0, 0}, {1, 0, 0}, {0, 1, 0}, {0, 0, 1}, {1, 1, 1}, {2, 1, 1}, {1, 2, 1}, {1, 1, 2}}, {{{1, 2, 3}, {1, 2, 4}, {2, 3, 4}, {1, 3, 4}}, {{5, 6, 7}, {5, 6, 8}, {6, 7, 8}, {5, 7, 8}}}]EulerCharacteristic[%]EulerCharacteristic 适用于网格区域:
MengerMesh[1, 3]EulerCharacteristic[%]属性和关系 (3)
用 EulerCharacteristic 计算简单多面体的 PolyhedronGenus:
𝒫 = Polyhedron[{{0, 0, 0}, {1, 0, 0}, {0, 1, 0}, {0, 0, 1}}, {{1, 2, 3}, {1, 2, 4}, {2, 3, 4},
{1, 3, 4}}];SimplePolyhedronQ[𝒫]1 - EulerCharacteristic[𝒫] / 2 == PolyhedronGenus[𝒫]𝒫 = Polyhedron[{{0, 0, 0}, {1, 0, 0}, {0, 1, 0}, {0, 0, 1}}, {{1, 2, 3}, {1, 2, 4}, {2, 3, 4},
{1, 3, 4}}];ConvexPolyhedronQ[𝒫]EulerCharacteristic[𝒫] == 2UniformPolyhedron 的欧拉示性数为 2:
UniformPolyhedron[{3, 5}]EulerCharacteristic[%]相关指南
-
▪
- 多面体
文本
Wolfram Research (2019),EulerCharacteristic,Wolfram 语言函数,https://reference.wolfram.com/language/ref/EulerCharacteristic.html.
CMS
Wolfram 语言. 2019. "EulerCharacteristic." Wolfram 语言与系统参考资料中心. Wolfram Research. https://reference.wolfram.com/language/ref/EulerCharacteristic.html.
APA
Wolfram 语言. (2019). EulerCharacteristic. Wolfram 语言与系统参考资料中心. 追溯自 https://reference.wolfram.com/language/ref/EulerCharacteristic.html 年
BibTeX
@misc{reference.wolfram_2026_eulercharacteristic, author="Wolfram Research", title="{EulerCharacteristic}", year="2019", howpublished="\url{https://reference.wolfram.com/language/ref/EulerCharacteristic.html}", note=[Accessed: 08-September-2026]}
BibLaTeX
@online{reference.wolfram_2026_eulercharacteristic, organization={Wolfram Research}, title={EulerCharacteristic}, year={2019}, url={https://reference.wolfram.com/language/ref/EulerCharacteristic.html}, note=[Accessed: 08-September-2026]}