/// <summary>
/// Gets label values for a series vector.
/// </summary>
/// <param name="Min">Smallest value.</param>
/// <param name="Max">Largest value.</param>
/// <param name="ApproxNrLabels">Number of labels.</param>
/// <param name="LabelType">Type of labels produced.</param>
/// <returns>Vector of labels.</returns>
public static DateTime[] GetLabels(DateTime Min, DateTime Max, int ApproxNrLabels, out LabelType LabelType)
{
List <DateTime> Labels = new List <DateTime>();
TimeSpan Span = Max - Min;
TimeSpan StepSize = Span == TimeSpan.Zero ? new TimeSpan(0, 0, 1) : new TimeSpan((Span.Ticks + (ApproxNrLabels >> 1)) / ApproxNrLabels);
int i, c;
for (i = 0, c = timeStepSizes.Length - 2; i < c; i++)
{
if (StepSize >= timeStepSizes[i] && StepSize < timeStepSizes[i + 1])
{
break;
}
}
int Nr1 = (int)Math.Round(Span.TotalSeconds / timeStepSizes[i].TotalSeconds);
int Diff1 = Math.Abs(ApproxNrLabels - Nr1);
int Nr2 = (int)Math.Round(Span.TotalSeconds / timeStepSizes[i + 1].TotalSeconds);
int Diff2 = Math.Abs(ApproxNrLabels - Nr1);
if (Diff1 < Diff2)
{
StepSize = timeStepSizes[i];
}
else
{
StepSize = timeStepSizes[i + 1];
}
if (StepSize.TotalDays >= 1)
{
DateTime TP;
TP = Min.Date;
if (Min.TimeOfDay != TimeSpan.Zero)
{
TP = TP.AddDays(1);
}
Nr1 = (int)Math.Floor((Max - TP).TotalDays);
Diff1 = Math.Abs(ApproxNrLabels - Nr1);
Nr2 = (int)Math.Floor((Max - TP).TotalDays / 2);
Diff2 = Math.Abs(ApproxNrLabels - Nr2);
if (Diff1 <= Diff2)
{
LabelType = LabelType.DateTimeDate;
while (TP <= Max)
{
Labels.Add(TP);
TP = TP.AddDays(1);
}
}
else
{
Nr1 = Nr2;
Diff1 = Diff2;
Nr2 = (int)Math.Floor((Max - TP).TotalDays / 7);
Diff2 = Math.Abs(ApproxNrLabels - Nr2);
if (Diff1 <= Diff2)
{
LabelType = LabelType.DateTimeDate; // Step every 2 days.
while (TP <= Max)
{
Labels.Add(TP);
TP = TP.AddDays(2);
}
}
else
{
Nr1 = Nr2;
Diff1 = Diff2;
Nr2 = (int)Math.Floor((Max - TP).TotalDays / 30);
Diff2 = Math.Abs(ApproxNrLabels - Nr2);
if (Diff1 <= Diff2)
{
LabelType = LabelType.DateTimeWeek;
i = (int)TP.DayOfWeek;
if (i == 0)
{
TP = TP.AddDays(1);
}
else if (i != 1)
{
TP = TP.AddDays(8 - i);
}
while (TP <= Max)
{
Labels.Add(TP);
TP = TP.AddDays(7);
}
}
else
{
Nr1 = Nr2;
Diff1 = Diff2;
Nr2 = (int)Math.Floor((Max - TP).TotalDays / 180);
Diff2 = Math.Abs(ApproxNrLabels - Nr2);
if (Diff1 <= Diff2)
{
LabelType = LabelType.DateTimeMonth;
if (TP.Day != 1)
{
TP = TP.AddDays(-TP.Day + 1).AddMonths(1);
}
while (TP <= Max)
{
Labels.Add(TP);
TP = TP.AddMonths(1);
}
}
else
{
Nr1 = Nr2;
Diff1 = Diff2;
Nr2 = (int)Math.Floor((Max - TP).TotalDays / 700);
Diff2 = Math.Abs(ApproxNrLabels - Nr2);
if (Diff1 <= Diff2)
{
LabelType = LabelType.DateTimeQuarter;
if (TP.Day != 1)
{
TP = TP.AddDays(-TP.Day + 1).AddMonths(1);
}
i = (TP.Month - 1) % 3;
if (i != 0)
{
TP = TP.AddMonths(3 - i);
}
while (TP <= Max)
{
Labels.Add(TP);
TP = TP.AddMonths(3);
}
}
else
{
LabelType = LabelType.DateTimeYear;
i = (int)Math.Floor(GetStepSize((Min - referenceTimestamp).TotalDays / 365.25,
(Max - referenceTimestamp).TotalDays / 365.25, ApproxNrLabels));
if (i == 0)
{
i++;
}
if (TP.Day > 1)
{
TP = TP.AddDays(-TP.Day + 1).AddMonths(1);
}
if (TP.Month > 1)
{
TP = TP.AddMonths(13 - TP.Month);
}
c = TP.Year % i;
if (c > 0)
{
TP = TP.AddYears(i - c);
}
while (TP <= Max)
{
Labels.Add(TP);
TP = TP.AddYears(i);
}
}
}
}
}
}
}
else
{
long Ticks = Min.Ticks;
long MaxTicks = Max.Ticks;
long Step = StepSize.Ticks;
long Residue = Ticks % Step;
if (Residue > 0)
{
Ticks += Step - Residue;
}
while (Ticks <= MaxTicks)
{
Labels.Add(new DateTime(Ticks));
Ticks += Step;
}
if (StepSize.TotalMinutes >= 1)
{
LabelType = LabelType.DateTimeShortTime;
}
else
{
LabelType = LabelType.DateTimeLongTime;
}
}
return(Labels.ToArray());
}
