Question

I would like to select from this data the group of points that have a distance value of <=40 and an activ value <=15. They have to be consecutive and there has to be a minimum of 3 of these. the code I started to use is with the rle() command. I can’t figure out how to link that information back to the data – to pull out those “runs” of both conditions >=3. I used the which command and the cbind to just look and check if the rle is working correctly. How do I then get the associated information of those groups? And then to make things even more complicated….I need to do this over 2 days of information at a time. Meaning, as you can see from the sample data below, that I have a Date/Time and I need to find all groups of >=3 locations where dist<40 AND activ<15 within a 48 hour window. The windows are exclusive and start at midnight and end at midnight 48 hours later The sample data I provided below is not sufficient for this last part but I would be willing to past that in if necessary.

run <- rle(Dist <= 40 & Activ <= 15)

tempdist <- Dist <= 40
tempactive <- Activ <= 15
which(tempdist == TRUE & tempactive == TRUE)
combine <- cbind(tempdist, tempactive)

structure(list(Fix = 1:15, Date = structure(c(1L, 1L, 1L, 2L, 
2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L), .Label = c("2010.06.23", 
"2010.06.24", "2010.06.25", "2010.06.26", "2010.06.27", "2010.06.28", 
"2010.06.29", "2010.06.30"), class = "factor"), Time = structure(c(86L, 
89L, 95L, 6L, 11L, 69L, 106L, 107L, 113L, 121L, 123L, 128L, 136L, 
14L, 22L), .Label = c("0:00:36", "0:00:39", "0:00:42", "0:00:48", 
"0:01:04", "0:01:28", "0:01:35", "1:00:15", "1:00:19", "1:00:49", 
"1:01:05", "1:01:29", "10:00:13", "10:00:35", "10:00:36", "10:00:42", 
"10:01:05", "10:01:11", "11:00:15", "11:00:20", "11:00:35", "11:00:42", 
"11:00:57", "11:01:05", "12:00:13", "12:00:19", "12:00:36", "12:00:42", 
"12:01:39", "12:03:03", "13:00:13", "13:00:32", "13:00:36", "13:00:47", 
"13:01:05", "13:01:52", "14:00:18", "14:00:36", "14:00:48", "14:01:04", 
"14:03:04", "15:00:35", "15:00:36", "15:01:04", "15:01:28", "15:01:36", 
"16:00:18", "16:00:19", "16:00:20", "16:00:36", "16:00:45", "16:03:05", 
"17:00:35", "17:00:42", "17:01:05", "17:01:11", "18:00:13", "18:00:35", 
"18:00:36", "18:00:37", "18:00:48", "18:01:04", "19:00:13", "19:00:27", 
"19:00:30", "19:00:35", "19:00:42", "19:00:43", "2:00:18", "2:00:36", 
"2:00:47", "2:00:54", "2:00:59", "2:01:30", "2:02:37", "20:00:13", 
"20:00:35", "20:00:36", "20:01:05", "21:00:14", "21:00:19", "21:00:20", 
"21:00:21", "21:00:35", "21:00:48", "21:01:08", "21:02:23", "22:00:35", 
"22:00:36", "22:00:38", "22:01:36", "22:03:04", "22:03:05", "23:00:15", 
"23:00:16", "23:00:20", "23:00:36", "23:01:05", "23:02:05", "23:03:03", 
"3:00:35", "3:00:36", "3:00:47", "3:00:48", "3:00:59", "3:01:58", 
"4:00:13", "4:00:17", "4:00:19", "4:00:35", "4:00:39", "5:00:16", 
"5:00:35", "5:00:36", "5:01:23", "6:00:13", "6:00:16", "6:00:18", 
"6:00:19", "6:00:35", "6:00:36", "7:00:18", "7:00:19", "7:00:36", 
"7:01:05", "7:01:22", "8:00:18", "8:00:35", "8:00:36", "8:00:42", 
"8:01:05", "9:00:13", "9:00:19", "9:00:35", "9:00:36", "9:00:53", 
"9:01:36"), class = "factor"), X = c(NA, 6351162.121, 6351137.038, 
6351180.514, 6351175.284, 6351189.867, 6351168.96, 6351230.592, 
6351187.825, 6351182.809, 6351179.366, 6351181.313, 6351157.538, 
6351180.688, 6351178.51), Y = c(NA, 436904.9145, 436928.697, 
436925.2068, 436946.703, 436961.3917, 436967.0372, 436934.0528, 
436978.3563, 436949.7116, 436963.6412, 436967.4078, 436949.5642, 
436964.5655, 436961.398), Temp = c(14L, 19L, 16L, 14L, 18L, 20L, 
18L, 14L, 13L, 15L, 17L, 13L, 16L, 18L, 20L), Activ = c(0.5, 
0.5, 57.5, 21.5, 0.5, 1, 48, 62.5, 42.5, 2, 9.5, 0.5, 0.5, 0.5, 
0.5), DateTime = structure(list(sec = c(8, 36, 16, 28, 5, 18, 
58, 13, 35, 36, 19, 35, 53, 35, 42), min = c(1L, 0L, 0L, 1L, 
1L, 0L, 1L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L), hour = c(21L, 22L, 
23L, 0L, 1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L, 11L), mday = c(23L, 
23L, 23L, 24L, 24L, 24L, 24L, 24L, 24L, 24L, 24L, 24L, 24L, 24L, 
24L), mon = c(5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 5L, 
5L, 5L, 5L), year = c(110L, 110L, 110L, 110L, 110L, 110L, 110L, 
110L, 110L, 110L, 110L, 110L, 110L, 110L, 110L), wday = c(3L, 
3L, 3L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L), yday = c(173L, 
173L, 173L, 174L, 174L, 174L, 174L, 174L, 174L, 174L, 174L, 174L, 
174L, 174L, 174L), isdst = c(0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 
0L, 0L, 0L, 0L, 0L, 0L, 0L)), .Names = c("sec", "min", "hour", 
"mday", "mon", "year", "wday", "yday", "isdst"), class = c("POSIXlt", 
"POSIXt"), tzone = "UTC"), DistX = c(NA, -25.0830000005662, 43.4760000007227, 
-5.23000000044703, 14.5829999996349, -20.9069999996573, 61.6320000002161, 
-42.7669999999925, -5.01599999982864, -3.4429999999702, 1.94699999969453, 
-23.7750000003725, 23.1500000003725, -2.17800000030547, -7.12799999956042
), DistY = c(NA, 23.7824999999721, -3.49020000000019, 21.4961999999941, 
14.6886999999988, 5.64550000004238, -32.9844000000157, 44.30349999998, 
-28.6447000000044, 13.9296000000322, 3.76659999997355, -17.8435999999638, 
15.0013000000035, -3.16750000003958, 0.131600000022445), Dist = c(NA, 
34.5653612056503, 43.6158694984158, 22.1232799205819, 20.6983525112342, 
21.6558149058434, 69.9033194303938, 61.5777265027509, 29.0805621350161, 
14.3487980388844, 4.24005714096063, 29.72616164217, 27.5855306584331, 
3.84405258179195, 7.12921472209522), LnDist = c(NA, 3.54285205938314, 
3.77542106345205, 3.09663044416928, 3.0300541082747, 3.07527400526048, 
4.24711313638682, 4.12030022240512, 3.37006998311865, 2.66366617834105, 
1.44457674579472, 3.39202752144892, 3.31729138374919, 1.34652716994060, 
1.96420109120712), TimeDif = c(59.4666666666667, 59.6666666666667, 
61.2, 59.6166666666667, 59.2166666666667, 61.6666666666667, 58.25, 
60.3666666666667, 60.0166666666667, 59.7166666666667, 60.2666666666667, 
60.3, 59.7, 60.1166666666667, 60), Velocity = c(NA, 0.579307729703637, 
0.712677606183265, 0.371092198835593, 0.349535927575022, 0.351175376851514, 
1.20005698592951, 1.02006173113337, 0.484541440738952, 0.240281295655334, 
0.0703549304362937, 0.492971171511941, 0.462069190258511, 0.0639432090123419, 
0.118820245368254), Heading = c(NA, 5.47117955593762, 1.65090330804596, 
6.04452351734706, 0.781787182793282, 4.97612800901505, 2.06219261575797, 
5.51543193207954, 3.31494594980981, 6.04087053685035, 0.477085335105382, 
4.06855550443118, 0.995825324541324, 3.74395368878987, 4.7308492849138
)), .Names = c("Fix", "Date", "Time", "X", "Y", "Temp", "Activ", 
"DateTime", "DistX", "DistY", "Dist", "LnDist", "TimeDif", "Velocity", 
"Heading"), row.names = c(NA, 15L), class = "data.frame")

Answer 1

I’m sure there are more efficient ways to do this, but it’s Friday and this approach works. rle() returns a list object containing lengths and values. As jimmyb mentioned, the key to to take what is returned from rle() and turn it into something useful for your data.frame. rep() is the weapon to do that.

#Your rle code
run <- rle(dat$Dist <= 40 & dat$Activ <= 15)

#Add columns for the length of the run and the value of that run
dat$run <- rep(run$lengths, run$lengths)
dat$cond <- rep(run$values, run$lengths)

#Subset the data based on the length and value
subset(dat, run >= 3 & cond)

Based on the sample data provides, that will return rows 10 – 15. Is that what you expected?