private IEnumerable <ActivityItem> GetTopActivityItems(DistanceBucket distanceBucket, IList <ActivityItem> activities, double topRatioOfActivitiesToUse)
{
var totalItems = activities.Count;
var itemsToTake = Convert.ToInt32(Math.Ceiling(totalItems * topRatioOfActivitiesToUse));
var activitiesBySpeed = activities.OrderByDescending(ai => ComputeNormalizedSpeed(distanceBucket, ai.Distance, ai.Speed)).ToList();
var topActivities = activitiesBySpeed.Take(itemsToTake);
return(topActivities);
}
private double ComputeNormalizedSpeed(DistanceBucket distanceBucket, double distance, double speed)
{
//using 6 percent degradation for each 2x distance
var df = .06;
var dp = distance > distanceBucket.Distance? 1: distance / distanceBucket.Distance;
var degradation = (1 - dp) * df;
var normalizedSpeed = speed * (1 - degradation);
return(normalizedSpeed);
}
private ActivityItem AggregrateForBucket(DistanceBucket distanceBucket, IList <ActivityItem> activityItems)
{
//var totalItems = activityItems.Count;
//var itemsToTake = Convert.ToInt32(Math.Ceiling(totalItems * Options.TopRatioOfActivitiesToUse));
var activitiesBySpeed = activityItems.OrderByDescending(ai => ComputeNormalizedSpeed(distanceBucket, ai.Distance, ai.Speed)).ToList();
var bestActivitiesForDistanceBucket = new List <ActivityItem>();
foreach (var activityItem in activitiesBySpeed)
{
bestActivitiesForDistanceBucket.Add(activityItem);
if (bestActivitiesForDistanceBucket.Sum(a => a.Distance) >= distanceBucket.Distance)
{
break;
}
}
var minStartTime = bestActivitiesForDistanceBucket.Min(ai => ai.StartDateTime);
var duration = bestActivitiesForDistanceBucket.Sum(a => a.Duration);
var distance = bestActivitiesForDistanceBucket.Sum(a => a.Distance);
return(new ActivityItem(minStartTime, distance, duration));
}
