private void AddColumn(DateTime start, HistoryRange range, decimal total, List <HistoryDataValue> bucket, Brush brush)
{
int century = start.Year / 100;
int year = start.Year;
string label = null;
switch (range)
{
case HistoryRange.All:
case HistoryRange.Year:
label = start.Year.ToString();
break;
case HistoryRange.Month:
year = year - (100 * century);
label = string.Format("{0:00}/{1:00}", start.Month, year);
break;
case HistoryRange.Day:
label = string.Format("{0:00}", start.Day);
break;
}
ColumnLabel clabel = new Charts.ColumnLabel(label);
HistoryChartColumn column = new HistoryChartColumn()
{
Amount = total, Label = clabel, Values = bucket, Brush = brush
};
clabel.Data = column;
collection.Add(column);
}
void BarChart_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
DependencyObject d = e.OriginalSource as DependencyObject;
if (e == null)
{
return;
}
while (d != null)
{
FrameworkElement f = d as FrameworkElement;
if (f != null && f.DataContext != null)
{
HistoryChartColumn data = f.DataContext as HistoryChartColumn;
if (data != null)
{
this.selection = data;
OnSelectionChanged();
return;
}
ColumnLabel label = f.DataContext as ColumnLabel;
if (label != null)
{
this.selection = label.Data;
OnSelectionChanged();
return;
}
}
d = VisualTreeHelper.GetParent(d);
}
}
private void ComputeLinearRegression()
{
// Compute linear regression
int count = collection.Count;
if (count == 0)
{
return;
}
// skip the first and/or last column if they don't seem to have enough data (they may have incomplete year/month).
double sum = (from c in collection select c.Values.Count()).Sum();
double avg = sum / count;
HistoryChartColumn first = collection[0];
HistoryChartColumn last = collection[count - 1];
double x = 0;
List <Point> points = new List <Point>();
foreach (HistoryChartColumn c in collection)
{
if ((c == last || c == last) && c.Values.Count() < (avg / 2))
{
// skip it.
continue;
}
points.Add(new Point(x++, (double)c.Amount));
}
double a, b; // y = a + b.x
MathHelpers.LinearRegression(points, out a, out b);
// create "Average" points that represent this line.
x = 0;
foreach (HistoryChartColumn c in collection)
{
double y = a + (b * x);
c.Average = (decimal)y;
x++;
}
}