R中rows/seconds的偏移平均计算

Question

我有以下数据集

Data <-structure(list(GPStime = structure(c(1581116832, 1581116833, 
1581116834, 1581116835, 1581116836, 1581116837, 1581116838, 1581116839, 
1581116840, 1581116841, 1581116842, 1581116843, 1581116844, 1581116845, 
1581116846, 1581116847, 1581116848, 1581116849, 1581116850, 1581116851, 
1581116852, 1581116853, 1581116854, 1581116855, 1581116856), class = c("POSIXct", 
"POSIXt"), tzone = "UTC"), MinimaxVel = c(3.091, 3.425, 4.617, 
4.277, 4.546, 5.396, 4.865, 4.802, 5.158, 4.381, 4.728, 5.394, 
4.346, 4.941, 5.191, 4.493, 5.189, 4.766, 4.671, 5.461, 4.321, 
4.985, 4.739, 4.537, 5.422), GarminVel = c(5.234, 5.207, 5.17358333333333, 
5.14013888888889, 5.10672222222222, 5.07327777777778, 5.03986111111111, 
5.00641666666667, 4.973, 4.861, 5.104, 5.076, 5.374, 4.871, 5.188, 
5.18627777777778, 5.18455555555556, 5.18280555555556, 5.18108333333333, 
5.17936111111111, 5.17763888888889, 5.17591666666667, 5.17419444444444, 
5.17244444444444, 5.17072222222222), VelDiff = c(-2.143, -1.782, 
-0.556583333333334, -0.863138888888889, -0.560722222222222, 0.322722222222223, 
-0.17486111111111, -0.204416666666667, 0.185, -0.48, -0.376, 
0.318000000000001, -1.028, 0.0700000000000003, 0.00300000000000011, 
-0.693277777777777, 0.00444444444444336, -0.416805555555556, 
-0.510083333333333, 0.28163888888889, -0.85663888888889, -0.190916666666666, 
-0.435194444444444, -0.635444444444444, 0.251277777777778)), row.names = c(NA, 
25L), class = "data.frame")

我想保留 MinimaxVel 列原样，但计算不同时间段内 GarminVel 的平均值。例如，我有一个 MinimaxVel 值和一个相应的 GarminVel 值。我需要一个新的 GarminVel 值来计算为 mean(GarminVel-1, GarminVel, GarminVel+1)。即我平均计算的时间段是 3 秒，偏移 1 秒。以下是前 3 秒的预期结果。

 GPStime MinimaxVel GarminVel   VelDiff
1 2020-02-07 23:07:12      3.091        NA        NA
2 2020-02-07 23:07:13      3.425  5.204861 -1.779861
3 2020-02-07 23:07:14      4.617  5.173574 -0.556574

我想在不同的时间段执行此操作，例如3 - 15 秒。我有谁能帮忙抵消吗？我看过 lag 和 rollmean 但还没有达到我想要的结果

谢谢

Answer 1

你可以在这里使用 rollmean :

transform(Data, GarminVel = zoo::rollmean(GarminVel, 3, fill = NA))

#              GPStime MinimaxVel GarminVel VelDiff
#1 2020-02-07 23:07:12       3.09        NA  -2.143
#2 2020-02-07 23:07:13       3.42      5.20  -1.782
#3 2020-02-07 23:07:14       4.62      5.17  -0.557
#4 2020-02-07 23:07:15       4.28      5.14  -0.863
#5 2020-02-07 23:07:16       4.55      5.11  -0.561
#6 2020-02-07 23:07:17       5.40      5.07   0.323
#...

在 rollmean 中，默认对齐方式是“居中”，它指定两个值之间的平均值。您可以根据需要将其更改为“左”或“右”。

R中rows/seconds的偏移平均计算

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