EntityCopies
EntityCopies[entity,n]
代表实体 entity 的 n 份副本.
更多信息
- 一般将一个实体指定为 Entity[type,canonicalname]. EntityValue[] 可以给出当前可用的实体类型列表.
- Entity 表达式可通过使用
界面来创建. - 副本 n 的数量可以为任意正整数.
范例
打开所有单元 关闭所有单元基本范例 (3)
EntityCopies[Entity["SportObject", "TennisBallType1"], 3][EntityProperty["SportObject", "Mass"]]EntityCopies[Entity["Star", "Sun"], 2]["Luminosity"]EntityCopies[Entity["SportObject", "AmericanFootballNFL"], 3][EntityProperty["SportObject", "Material"]]范围 (4)
EntityCopies 表达式可与列表中常规实体一起用:
EntityValue[{Entity["SportObject", "TennisBallType1"], EntityCopies[Entity["SportObject", "TennisBallType1"], 3], Entity["SportObject", "GolfBall"], Entity["SportObject", "VolleyballBeach"]}, "Mass"]EntityCopies 的扩展属性值可产生所有副本的总数值:
EntityCopies[Entity["SportObject", "BasketballNBA"], 2][EntityProperty["SportObject", "Volume"]]由于体积是扩展属性,所以两个篮球的体积值为单个篮球体积的两倍:
Entity["SportObject", "BasketballNBA"][EntityProperty["SportObject", "Volume"]]%% / %EntityCopies 的无扩展属性则为每个副本重复其属性值:
EntityCopies[Entity["SportObject", "GolfBall"], 2][EntityProperty["SportObject", "Shape"]]EntityCopies[Entity["SportObject", "BasketballNBA"], 3]["InflationPressure"]一个实体的多个副本的计算值可能返回的结果为,总数值加上不同类型属性值列表的组合(即:有些可扩展有些不可):
EntityCopies[Entity["Star", "Sun"], 10][{EntityProperty["Star", "Mass"], EntityProperty["Star", "Density"]}]推广和延伸 (1)
对于 EntityValue 而言,一个实体 entity 的 n 个副本的 EntityGroup 与 EntityCopies[entity,n] 等价:
EntityValue[EntityGroup[Table[Entity["Building", "EiffelTower::5h9w8"], {2}]], "Height"]EntityValue[EntityCopies[Entity["Building", "EiffelTower::5h9w8"], 2], "Height"]属性和关系 (3)
EntityCopies[Entity["SportObject", "GolfBall"], 0][EntityProperty["SportObject", "Mass"]]EntityCopies[Entity["SportObject", "GolfBall"], 0][EntityProperty["SportObject", "Material"]]对于一个单个副本,则 EntityCopies 不进行计算:
EntityCopies[Entity["SportObject", "GolfBall"], 1]对一个包含单个副本的 EntityCopies 表达式的操作与对正常实体 Entity 的操作等价:
EntityCopies[Entity["SportObject", "GolfBall"], 1][EntityProperty["SportObject", "Mass"]]Entity["SportObject", "GolfBall"][EntityProperty["SportObject", "Mass"]]% === %%可能存在的问题 (2)
若尝试给出无效的实体数量,则返回的是 Missing 的一个适当形式:
EntityCopies[Entity["Star", "Sun"], -1]["Mass"]EntityCopies 表达式还可以返回不同单位的结果,而非一类数值:
EntityCopies[Entity["Particle", "Electron"], 10]["Mass"]UnitConvert[Quantity[10, "ElectronMass"], "SI"]% == %%相关指南
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- 知识表示和访问
文本
Wolfram Research (2015),EntityCopies,Wolfram 语言函数,https://reference.wolfram.com/language/ref/EntityCopies.html.
CMS
Wolfram 语言. 2015. "EntityCopies." Wolfram 语言与系统参考资料中心. Wolfram Research. https://reference.wolfram.com/language/ref/EntityCopies.html.
APA
Wolfram 语言. (2015). EntityCopies. Wolfram 语言与系统参考资料中心. 追溯自 https://reference.wolfram.com/language/ref/EntityCopies.html 年
BibTeX
@misc{reference.wolfram_2026_entitycopies, author="Wolfram Research", title="{EntityCopies}", year="2015", howpublished="\url{https://reference.wolfram.com/language/ref/EntityCopies.html}", note=[Accessed: 08-October-2026]}
BibLaTeX
@online{reference.wolfram_2026_entitycopies, organization={Wolfram Research}, title={EntityCopies}, year={2015}, url={https://reference.wolfram.com/language/ref/EntityCopies.html}, note=[Accessed: 08-October-2026]}