[R] Hot Air Balloon Weather Briefings

[Jim Lemon]

Hi Philip,
Not very elegant, but:

phdf<-read.table(text="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",
 header=TRUE,stringsAsFactors=FALSE)
keep<-rep(TRUE,length(phdf$Speed))
for(mini in unique(phdf$Minute))
 if(all(phdf$Speed[phdf$Minute == mini] == 0))
  keep[phdf$Minute == mini]<-FALSE
phdf<-phdf[keep,]

Jim

On Sat, Aug 15, 2020 at 6:59 AM Philip <herd_dog using 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]]
>
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