EventSeriesLookup[eseries,time]
给出 EventSeries 对象 eseries 中距离 time 最近的事件.
EventSeriesLookup[eseries,time,ptype]
给出 eseries 中在类型 ptype 下与 time 邻近的事件.
EventSeriesLookup[eseries,time,ptypeprop]
给出与 time 邻近的事件的属性 prop.
EventSeriesLookup[eseries,time,ptype,n]
给出最多 n 个近端事件.
EventSeriesLookup[eseries,time,ptype,{n,r}]
返回最多 n 个与 time 时间间隔不超过 r 的事件.
EventSeriesLookup
EventSeriesLookup[eseries,time]
给出 EventSeries 对象 eseries 中距离 time 最近的事件.
EventSeriesLookup[eseries,time,ptype]
给出 eseries 中在类型 ptype 下与 time 邻近的事件.
EventSeriesLookup[eseries,time,ptypeprop]
给出与 time 邻近的事件的属性 prop.
EventSeriesLookup[eseries,time,ptype,n]
给出最多 n 个近端事件.
EventSeriesLookup[eseries,time,ptype,{n,r}]
返回最多 n 个与 time 时间间隔不超过 r 的事件.
更多信息
- EventSeriesLookup 通常用于提取在时间上接近某个特定时刻的事件.
- EventSeriesLookup 函数返回给定事件序列的 {timestamp,value} 对列表. 输出列表可以为空.
- time 的可能取值可以是数字,也可以是 DateObject 表达式.
- 可能的邻近类型 ptype 包括:
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"Nearest" 时间戳最接近 time 的事件 "Previous" 在 time 之前最接近的事件 "Next" 在 time 之后最接近的事件 - EventSeriesLookup[eseries,time] 等价于 EventSeriesLookup[eseries,time,"Nearest"].
- 可能的属性 prop 包括:
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"Element" 近端事件 {{t1,v1},…} "Index" 近端事件的索引 "Timestamps" 时间戳 {t1,..} "Values" 值 {v1,…} "Distance" 距离 {t1-time,…} "EventSeries" 近端事件的 EventSeries - EventSeriesLookup[eseries,time,ptype] 等价于 EventSeriesLookup[eseries,time,ptype"Element"].
- 半径 r 应为一个数值,或一个带有时间单位的 Quantity.
范例
打开所有单元 关闭所有单元基本范例 (2)
eseries = EventSeries[Range[19], { DateObject[{2026, 2, 1}, "Day"], DateObject[{2026, 2, 28}, "Day"], "BusinessDay"}]EventSeriesLookup[eseries, DateObject[{2026, 2, 15}, "Day"]]EventSeriesLookup[eseries, DateObject[{2026, 2, 15}, "Day"], "Next"]EventSeriesLookup[eseries, DateObject[{2026, 2, 15}, "Day"], "Previous"]eseries = EventSeries[<||>, {{0, 1.2, 1.7, 2.1, 2.7, 3.5}}];EventSeriesLookup[eseries, 2, "Nearest"]EventSeriesLookup[eseries, 2, "Nearest" -> "Timestamp", 4]//Normal范围 (10)
使用 EventSeriesLookup 并采用不同的邻近类型:
eseries = EventSeries[{a, b, c, d}, {{0, 1, 2, 3}}]EventSeriesLookup[eseries, 1 / 2, "Previous"]EventSeriesLookup[eseries, 1 / 2, "Next"]EventSeriesLookup[eseries, 1 / 2, "Nearest"]EventSeriesLookup[eseries, 1 / 2]当两个时间戳与输入时间的接近程度相同时,这两个时间戳都会被包含在内:
eseries = EventSeries[{a, b, c, d, e}, {{0, 1, 2, 3, 4}}]EventSeriesLookup[eseries, 1.5]EventSeriesLookup 可以返回任意数量的事件:
eseries = EventSeries[{a, b, c, d, e, f}, {{0, 0, 1, 1, 1, 2}}]EventSeriesLookup[eseries, 1 / 3]EventSeriesLookup[eseries, 2 / 3]EventSeriesLookup[eseries, 1 / 2]当 EventSeries 具有重复的时间戳时,默认情况下会包含这些时间戳对应的所有值:
eseries = EventSeries[{a, b, c, d, e}, {{0, 0, 1, 1, 1}}]EventSeriesLookup[eseries, 2 / 3, "Next"]EventSeriesLookup[eseries, 2 / 3, "Next", 2]EventSeriesLookup 在计数为 n 时,最多返回 n 个结果:
eseries = EventSeries[Range[10], {RandomReal[1, 10]}]EventSeriesLookup[eseries, .3, "Previous", 15]将 EventSeriesLookup 与不同属性一起使用:
eseries = EventSeries[{a, b, c, d, e, f}, {{0, 0.1, 0.1, 0.3, 0.5, 0.5}}]EventSeriesLookup[eseries, .4, "Nearest" -> "Element"]EventSeriesLookup[eseries, .4, "Nearest" -> "Index"]EventSeriesLookup[eseries, .4, "Nearest" -> "Timestamp"]//NormalEventSeriesLookup[eseries, .4, "Nearest" -> "Value"]//NormalEventSeriesLookup[eseries, .4, "Nearest" -> "Distance"]//NormalEventSeriesLookup[eseries, .4, "Nearest" -> "EventSeries"]eseries = EventSeries[{a, b, c, d, e}, {{0, 0, 1, 1, 1}}]inds = EventSeriesLookup[eseries, .618, "Nearest" -> "Index"]该结果可与 Part 一起使用,以获取新的 EventSeries:
eseries[[inds]]Normal[%]EventSeriesLookup[eseries, .618, "Nearest"]BlockRandom[dates = RandomDate[100], RandomSeeding -> 1234];
es = EventSeries[Range[100], {dates}, DateGranularity -> "Day"]june = DateObject[{2026, 6}, "Month"];
EventSeriesLookup[es, june]EventSeriesLookup[es, june, "Previous"]以 EventSeries 的形式返回六月之后的所有事件:
EventSeriesLookup[es, june, "Next" -> "EventSeries", Infinity]BlockRandom[dates = RandomDate[250], RandomSeeding -> 1234];
eseries = EventSeries[Range[250], {dates}, DateGranularity -> "Day"]查找从三月十五日(Ides of March)到最近事件的所有距离:
day = DateObject[{2026, 3, 15}];
dist = EventSeriesLookup[eseries, day, "Nearest" -> "Distance"]结果中距离 0 被重复列出,因为在原始事件序列中有多个“三月十五日”实例:
Normal[dist]当计数更大时,可以明显看出,近端事件是按距离递增的顺序给出的:
EventSeriesLookup[eseries, day, "Nearest" -> "Distance", 6] //NormalEventSeriesLookup[eseries, day, "Nearest" -> "Timestamp", 6] //NormalBlockRandom[dates = RandomDate[100], RandomSeeding -> 1234];
es = EventSeries[Range[100], {dates}, DateGranularity -> "Day"]day = DateObject[{2026, 3, 15}];EventSeriesLookup[es, day, "Nearest", {Infinity, Quantity[1, "Weeks"]}]EventSeriesLookup[es, day, "Next", {Infinity, Quantity[1, "Weeks"]}]属性和关系 (2)
EventSeriesLookup 使用默认的 ptype 时,等价于对时间戳使用 Nearest:
eseries = EventSeries[{Subscript[x, 1], Subscript[x, 2], Subscript[x, 3], Subscript[x, 4], Subscript[x, 5], Subscript[x, 6], Subscript[x, 7]}, {{1, 2, 2, 3, 3, 3, 4}}]EventSeriesLookup[eseries, 2.5, "Nearest" -> "Timestamp"]//NormalNearest[eseries["Timestamps"], 2.5]EventSeriesLookup 更快,因为它利用了时间戳已排序这一事实:
BlockRandom[times = RandomInteger[10 ^ 6, 10 ^ 6], RandomSeeding -> 1234];
es = EventSeries[<||>, {times}];RepeatedTiming[EventSeriesLookup[es, 5 10 ^ 5, "Nearest" -> "Index"]]RepeatedTiming[Nearest[times -> "Index", 5 10 ^ 5]]RepeatedTiming[Nearest[Sort[times] -> "Index", 5 10 ^ 5]]EventSeriesLookup 和 TimeSeriesWindow 都可用于提取一个子序列:
es = EventSeries[Range[20], {DateObject[{2026, 3, 25}]}]EventSeriesLookup[es, DateObject[{2026, 3, 31}], "Next" -> "EventSeries", Infinity]% === TimeSeriesWindow[es, {DateObject[{2026, 4, 1}], Automatic}]相关指南
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- 事件序列处理
文本
Wolfram Research (2026),EventSeriesLookup,Wolfram 语言函数,https://reference.wolfram.com/language/ref/EventSeriesLookup.html.
CMS
Wolfram 语言. 2026. "EventSeriesLookup." Wolfram 语言与系统参考资料中心. Wolfram Research. https://reference.wolfram.com/language/ref/EventSeriesLookup.html.
APA
Wolfram 语言. (2026). EventSeriesLookup. Wolfram 语言与系统参考资料中心. 追溯自 https://reference.wolfram.com/language/ref/EventSeriesLookup.html 年
BibTeX
@misc{reference.wolfram_2026_eventserieslookup, author="Wolfram Research", title="{EventSeriesLookup}", year="2026", howpublished="\url{https://reference.wolfram.com/language/ref/EventSeriesLookup.html}", note=[Accessed: 07-September-2026]}
BibLaTeX
@online{reference.wolfram_2026_eventserieslookup, organization={Wolfram Research}, title={EventSeriesLookup}, year={2026}, url={https://reference.wolfram.com/language/ref/EventSeriesLookup.html}, note=[Accessed: 07-September-2026]}