Stat Assembly > Stat Assembly Interfaces > IStatistics > IStatistics.Forecast
Forecast(Value: Double; KnownYs: Array; KnownXs: Array): Double;
Value. Index of the point whose value is predicted;
KnownYs. Dependent array of data;
KnownXs. Independent array of data.
NOTE. KnownYs and KnownXs must not be empty and must contain equal number of points.
The Forecast method calculates a future value by existing values.
Predicted value is a Y value corresponding to specified X value. Known values are the KnownYs value and the KnownXs value and a new value is predicted using the linear regression.
To execute the example, add a link to the Stat system assembly.
Sub UserProc;
Var
st: Statistics;
d0: Double;
y, x: Array Of Double;
Begin
y := New Double[10];
x := New Double[10];
y[00] := 1.6; x[00] := 2;
y[01] := 1.7; x[01] := 4;
y[02] := 1.8; x[02] := 2;
y[03] := 1.9; x[03] := 5;
y[04] := 2; x[04] := 12;
y[05] := 2.1; x[05] := 6;
y[06] := 2.2; x[06] := 15;
y[07] := 2.3; x[07] := 17;
y[08] := 2.4; x[08] := 14;
y[09] := 2.8; x[09] := 3;
st := New Statistics.Create;
d0 := st.Forecast(30,y,x);
If st.Status <> 0 Then
Debug.WriteLine(st.Errors);
Else
Debug.WriteLine("Forecast: " + d0.ToString);
End If;
End Sub UserProc;
Executing the example shows a forecast value in the console window:
Unit execution started
Forecast: 2.60857142857143
Unit execution finished
See also:
IStatistics | Linear regression
