IStatistics.Forecast

Syntax

Forecast(Value: Double; KnownYs: Array; KnownXs: Array): Double;

Parameters

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.

Description

The Forecast method calculates a future value by existing values.

Comments

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.

Example

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 this example shows a forecast value in the console window:

Module execution started

Forecast: 2.6085714285714285

Module execution finished