Hot Air Balloon Weather Briefings
Well which is it?: "I want to eliminate the data for minute 30 but keep the data for minute 31 because the balloon starts to move again at second 17. " or "It would be even better if I could delete the rows where there were ten consecutive zero speed entries such as from minute 30 second 17 to minute 31 second 11." If you want to delete say data with >= 10 consecutive 0's, ?rle is your friend: rle(phdf$Speed) Run Length Encoding lengths: int [1:10] 15 1 1 1 1 1 1 1 1 1 values : num [1:10] 0 0.402649 0.671081 1.588225 2.438261 2.706693 2.930386 3.310666 3.198819 3.422512 e.g.
z <- rle(phdf$Speed)$lengths
## which gives:
z
[1] 15 1 1 1 1 1 1 1 1 1
rep(z>9,z)
[1] TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE [11] TRUE TRUE TRUE TRUE TRUE FALSE FALSE FALSE FALSE FALSE [21] FALSE FALSE FALSE FALSE ##Thus:
phdf[ rep(z<10, z), ]
Minute Second Speed 16 31 17 0.402649 17 31 23 0.671081 18 31 29 1.588225 19 31 35 2.438261 20 31 41 2.706693 21 31 47 2.930386 22 31 53 3.310666 23 31 59 3.198819 24 32 5 3.422512 But of course, this probably isn't what you meant. So further clarification is needed. Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into it." -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
On Fri, Aug 14, 2020 at 1:59 PM Philip <herd_dog at cox.net> wrote:
I?m trying to compare National Weather Service Rapid Update Forecast (RAP)
data to GPS breadcrumbs collected by a really clever Apple Phone Ap that
lays down longitude, latitude, altitude, compass direction, and speed every
six seconds. Below is a small subset of the GPS data from another
flight.
I want to delete the rows where the balloon does not move (Speed column)
for a full minute assuming that it is sitting on the ground ? beginning of
the flight, changing passengers, or waiting for the chase crew at the end
of the flight. for example, I want to eliminate the data for minute 30 but
keep the data for minute 31 because the balloon starts to move again at
second 17. Any suggestions? I?ve tried putzing around with multiple lags
without success.
Minute Second Speed
29 47 0
29 53 0
29 59 0
30 5 0
30 11 0
30 17 0
30 23 0
30 29 0
30 35 0
30 41 0
30 47 0
30 53 0
30 59 0
31 5 0
31 11 0
31 17 0.402649
31 23 0.671081
31 29 1.588225
31 35 2.438261
31 41 2.706693
31 47 2.930386
31 53 3.310666
31 59 3.198819
32 5 3.422512
It would be even better if I could delete the rows where there were ten
consecutive zero speed entries such as from minute 30 second 17 to minute
31 second 11.
Thanks,
Philip Heinrich
[[alternative HTML version deleted]]
______________________________________________ R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.