public LinearProgression Shifted(TimeSpan offset)
{
LinearProgression shifted = new LinearProgression();
foreach (ListItemStats <DateTime, double> stats in this.searchHelper.AllItems)
{
shifted.Add(stats.Key.Add(offset), stats.Value);
}
return(shifted);
}
public LinearProgression Smoothed(TimeSpan windowSize)
{
// make a List of the cumulative time spent
DateTime minDate = this.Owner.DiscoveryDate;
IEnumerable <ListItemStats <DateTime, ParticipationAndSummary> > items = this.searchHelper.AllItems;
LinearProgression cumulatives = new LinearProgression();
// first sort the starts and ends
StatList <DateTime, double> deltaIntensities = new StatList <DateTime, double>(new DateComparer(), new FloatAdder());
foreach (ListItemStats <DateTime, ParticipationAndSummary> item in items)
{
deltaIntensities.Add(item.Value.Participation.StartDate, 1);
deltaIntensities.Add(item.Value.Participation.EndDate, -1);
}
if (deltaIntensities.NumItems < 1)
{
return(new LinearProgression());
}
DateTime maxDate = deltaIntensities.GetLastValue().Key;
// now add up the (possibly overlapping) values
double intensity = 0;
DateTime prevDate = minDate;
double sum = 0;
foreach (ListItemStats <DateTime, double> deltaIntensity in deltaIntensities.AllItems)
{
double duration = deltaIntensity.Key.Subtract(prevDate).TotalSeconds;
sum += intensity * duration;
intensity += deltaIntensity.Value;
cumulatives.Add(deltaIntensity.Key, sum);
prevDate = deltaIntensity.Key;
}
// find what's in the sliding window by subtracting the cumulative from the shifted cumulative
LinearProgression shiftedCumulatives = cumulatives.Shifted(windowSize);
if (windowSize.TotalSeconds > 0)
{
cumulatives.Add(maxDate.Add(windowSize), sum);
LinearProgression result = cumulatives.Minus(shiftedCumulatives);
return(result);
}
else
{
shiftedCumulatives.Add(maxDate, sum);
LinearProgression result = shiftedCumulatives.Minus(cumulatives);
return(result);
}
}
public LinearProgression Minus(LinearProgression other)
{
StatList <DateTime, double> union = this.searchHelper.Union(other.searchHelper);
LinearProgression diff = new LinearProgression();
DateTime prevDate = new DateTime();
foreach (ListItemStats <DateTime, double> item in union.AllItems)
{
DateTime when = item.Key;
if (when == prevDate)
{
// skip duplicates
continue;
}
// this relies on this.searchHelper.optimizeForLocality = true and other.searchHelper.optimizeForLocality = true for it to be fast
double ourValue, theirValue;
ourValue = this.GetValueAt(when, false).Value.Mean;
theirValue = other.GetValueAt(when, false).Value.Mean;
double value = ourValue - theirValue;
diff.Add(item.Key, value);
}
return(diff);
}
