Displaying 2 results from an estimated 2 matches for "flightfact".
2011 Jul 17
1
How to speed up interpolation
df is a very large data frame with arrival estimates for many flights
(DF$flightfact) at random times (df$PredTime). The error of the estimate
is df$dt.
My problem is that I want to know the prediction error at each minute
before landing. This code works, but is very slow, and dominates
everything. I tried using split(), but that rapidly ate up my 12 GB of
memory. So, is there a be...
2011 Aug 27
2
Am having trouble calling a function
...t;T")
#Plot individual flight data
dfm = df
dfm = dfm[!df$MsgType=="AS",] # Eliminate AS messages
dfm$MsgType=drop.levels(dfm$MsgType)
dfm = dfm[as.numeric(dfm$PredTime) < 60.0,]
dfm$tc= as.factor(floor(dfm$PredTime/10.0)) # get 10-minute bin
dfm$flightfact = drop.levels(dfm$flightfact)
row.names(dfm) = seq(1:dim(dfm)[1])
#Find max and min error for each flight
library(zoo)
maxes = tapply(dfm$dt,dfm$flightfact,FUN=max) # Returns a list
mins = tapply(dfm$dt,dfm$flightfact,FUN=min)
mdf = data.frame(flight=index(maxes), maxes...