private string GetFormula(TrendLineTypeEnum tlt, double[] k)
{
string s = "";
switch (tlt)
{
case TrendLineTypeEnum.Polynom:
return(GetFormula(DataType.Poly2, k));
case TrendLineTypeEnum.Exponent:
return(GetFormula(DataType.Expo, k));
case TrendLineTypeEnum.Logarithmic:
return(GetFormula(DataType.Log, k));
case TrendLineTypeEnum.Power:
return(GetFormula(DataType.Pow, k));
case TrendLineTypeEnum.Fourier:
return(GetFormula(DataType.Fourier2, k));
default:
break;
}
return(s);
}
private void UpdateFormulaLabel()
{
C1.Win.C1Chart.Label lbl;
if (c1Chart1.ChartLabels.LabelsCollection.Count < 2)
{
// create formula label
lbl = c1Chart1.ChartLabels.LabelsCollection.AddNewLabel();
lbl.AttachMethod = AttachMethodEnum.Coordinate;
lbl.AttachMethodData.X = c1Chart1.ChartArea.PlotArea.Location.X + c1Chart1.ChartArea.PlotArea.Size.Width / 2;
lbl.AttachMethodData.Y = c1Chart1.ChartArea.PlotArea.Location.Y + 20;
lbl.Style.BackColor = Color.FromArgb(192, Color.LightBlue);
lbl.Style.GradientStyle = GradientStyleEnum.None;
lbl.Style.Border.BorderStyle = BorderStyleEnum.Solid;
lbl.Style.Border.Color = Color.DarkBlue;
lbl.Style.Border.Rounding.All = 15;
lbl.Style.VerticalAlignment = AlignVertEnum.Center;
lbl.Compass = LabelCompassEnum.North;
}
else
{
lbl = c1Chart1.ChartLabels[1];
}
TrendLine tl = null;
if (c1Chart1.ChartGroups[0].ChartData.TrendsList.Count > 0)
{
tl = c1Chart1.ChartGroups[0].ChartData.TrendsList[0];
}
else
{
return;
}
RegressionStatistics rs = tl.RegressionStatistics;
if (rs == null || rs.Coeffs == null || !cbViewFormula.Checked)
{
lbl.Visible = false;
return;
}
TrendLineTypeEnum tlt = (TrendLineTypeEnum)cbTrendType.SelectedItem;
string s_regr = GetFormula(tlt, rs.Coeffs);
string s_exact = GetFormula(dtLastGenerated, k);
if (s_regr.Length > 0 && s_exact.Length > 0)
{
lbl.Visible = true;
lbl.Text = string.Format("Data formula: {0}\n\nRegression formula: {1}", s_exact, s_regr);
}
else if (s_regr.Length > 0)
{
lbl.Visible = true;
lbl.Text = string.Format("Regression formula: {1}", s_exact, s_regr);
}
else
{
lbl.Visible = false;
}
}
