ICurveEstimationExplanatory.IsTrend

Syntax

IsTrend: Boolean;

Description

The IsTrend property determines how an explanatory series is set, as an automatically generated time series or generated by the user.

Comments

Available values:

True. Default value. The explanatory series is an automatically generated time series. The first series point is set via the ICurveEstimationExplanatory.ReferencePoint property.
False. The explanatory series is set by the user via the ICurveEstimationExplanatory.Serie property.

Example

To execute the example, add a link to the Stat system assembly.

Sub Main;
Var
    trend: SmCurveEstimation;
    d0: Double;
    status, i: Integer;
    ar: Array[25] Of Double;
Begin
    trend := New SmCurveEstimation.Create;
    ar[00] := 4110; ar[01] := 4280; ar[02] := 4459; ar[03] := 4545; ar[04] := 4664;
    ar[05] := 4861; ar[06] := 5195; ar[07] := 5389; ar[08] := 5463; ar[09] := 5610;
    ar[10] := 5948; ar[11] := 6218; ar[12] := 6521; ar[13] := 6788; ar[14] := 7222;
    ar[15] := 7486; ar[16] := 7832; ar[17] := 8153; ar[18] := 8468; ar[19] := 9054;
    ar[20] := 9499; ar[21] := 9866; ar[22] := 10217; ar[23] := 10763; ar[24] := 10683;
    trend.Explained.Value := ar;
    trend.Explanatory.IsTrend := True; // explanatory series - automatically generated time series
    trend.Explanatory.ReferencePoint := 99; // the first point of explanatory time series
    trend.ModelPeriod.LastPoint := 20;
    trend.ForecastLastPoint := 30;
    trend.SeasonalComponent.Mode := SeasonalityType.Additive;
    trend.SeasonalComponent.Cycle := 4;
    status := trend.Execute;
    If status <> 0 Then
        Debug.WriteLine(trend.Errors);
        Else
            For i := 0 To 10 Do
                d0 := trend.DependenceForms.Item(i).CriterionValue;
                Debug.WriteLine(trend.DependenceForms.Item(i).Name + ": " + d0.ToString);
            End For;
    End If;
End Sub Main;

After executing the example the console window displays the following results:

Linear: 0.97313512972825955

Quadratic: 0.99853888260620438

Polynomial: 0.99862028141069137

Compound: 0.99520880118290411

Growth: 0.99520880118290367

Logarithmic: 0.96515890582692698

Hyperbolic: 0.98683741835754846

Exponential: 0.99520880118290367

Inverse: 0.95615061432260506

Power: 0.99166441790463866

Logistic: 0.18896590355019971