search for: predtime

Displaying 2 results from an estimated 2 matches for "predtime".

2011 Aug 27
2
Am having trouble calling a function
...irport(x, base)} ) And doAirport has # analyze the flights for a given airport doAirport = function(df, base) { # Get rid of unused runway factor levels (from other airports) df$lrw <- drop.levels(df$lrw) # In gdata package # Drop messages from after the landing time df = df[df$PredTime >= 0.0,] airport = as.character(df[1,"Dest"]) #print it out airport date = strptime(df[1,"on"], format="%Y-%m-%d") rwys = factor(unique(df$lrw), ordered=TRUE) # Get the names of the runways rwys = as.vector(rwys) nrwys = length(rwys)...
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 better R way of doing this? Tha...