这个问题建立在这个问题之上:
我的问题:
下面粘贴的代码使用 计算 7 天内的最大斜率length(HDD)
。我想更有区别,我只希望连续 7 天计算 MaxSlope。
例如,从 2004 年 12 月 26 日到 2004 年 12 月 30 日的数据中存在差距。仅考虑我在此处复制的这部分数据,MaxSlope 应仅针对 2004-12-23 和 2004-12-24 计算。所有其他日期都应插入“NA”。该数据集将增长到数百万条记录,因此效率很重要。
注意:我将我的 data.frame 子集化以仅提供此处重要的列。MaxSlope 代码中的by
语句很重要,因为它适用于整个 data.frame。
我不知道从哪里开始连续日期计算。有任何想法吗?
谢谢!
我用来计算最大斜率的代码:
RawByDayALL <- data.table(RawByDayALL)
RawByDayALL[, MaxSlope := if(length(HDD)<7) {rep(NA_real_, length(HDD))} else {filter(HDD, c(1,1,1,1,1,1,0)/7)}, by=list(WinterID, SiteID, SubstrateConcat)]
RawByDayALL[is.na(MaxSlope), MaxSlope := -99L]
我的数据结构:
> dput(RawByDayALL[650:660])
structure(list(WinterID = structure(c(6L, 6L, 6L, 6L, 6L, 6L,
6L, 6L, 6L, 6L, 6L), .Label = c("2002", "2002_2003", "2003",
"2003_2004", "2004", "2004_2005", "2005", "2005_2006", "2006",
"2006_2007", "2007", "2007_2008", "2008"), class = "factor"),
Date = structure(c(12771, 12772, 12773, 12774, 12775, 12776,
12777, 12778, 12782, 12783, 12784), class = "Date"), SiteID = structure(c(1L,
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = "NW_SB", class = "factor"),
SubstrateConcat = structure(c(2L, 2L, 2L, 2L, 2L, 2L, 2L,
2L, 2L, 2L, 2L), .Label = c("B_A", "B_B"), class = "factor"),
HDD = c(17.3533333333333, 35.1066666666667, 82.6266666666667,
51.68, 36.22, 39.6066666666667, 38.0533333333333, 47.8333333333333,
4.18, 9.66, 1.5), MaxSlope = c(30.4104761904762, 33.3885714285714,
37.5133333333333, 40.4704761904762, 42.2885714285714, 31.0819047619048,
25.0790476190476, 20.1190476190476, 14.6019047619048, 9.19428571428571,
2.6552380952381)), .Names = c("WinterID", "Date", "SiteID",
"SubstrateConcat", "HDD", "MaxSlope"), class = c("data.table",
"data.frame"), row.names = c(NA, -11L), .internal.selfref = <pointer: 0x0000000000100788>)
数据的一部分是什么样的:
WinterID Date SiteID SubstrateConcat HDD MaxSlope
650 2004_2005 2004-12-19 NW_SB B_B 17.35333333 30.41047619
651 2004_2005 2004-12-20 NW_SB B_B 35.10666667 33.38857143
652 2004_2005 2004-12-21 NW_SB B_B 82.62666667 37.51333333
653 2004_2005 2004-12-22 NW_SB B_B 51.68000000 40.47047619
654 2004_2005 2004-12-23 NW_SB B_B 36.22000000 42.28857143
655 2004_2005 2004-12-24 NW_SB B_B 39.60666667 31.08190476
656 2004_2005 2004-12-25 NW_SB B_B 38.05333333 25.07904762
657 2004_2005 2004-12-26 NW_SB B_B 47.83333333 20.11904762
658 2004_2005 2004-12-30 NW_SB B_B 4.18000000 14.60190476
659 2004_2005 2004-12-31 NW_SB B_B 9.66000000 9.19428571
660 2004_2005 2005-01-01 NW_SB B_B 1.50000000 2.65523810
已编辑以包括@eddi 提供的答案。感谢您的简单修复!
RawByDayALL <- data.table(RawByDayALL)
RawByDayALL[, MaxSlope := if(length(HDD)<7) {rep(NA_real_, length(HDD))} else {filter(HDD, c(1,1,1,1,1,1,0)/7)}, by=list(WinterID, SiteID, SubstrateConcat, cumsum(diff(c(Date[1], as.IDate(Date))) > 1))]
RawByDayALL[is.na(MaxSlope), MaxSlope := -99L]