IStatistics.Slope

Fore Syntax

Slope(KnownYs: Array; KnownXs: Array): Double;

Fore.NET Syntax

Slope(KnownYs: System.Array; KnownXs: System.Array): double;

Parameters

KnownYs. Independent series.

KnownXs. Dependent series.

Description

The Slope method returns the slope of the linear regression line.

Comments

The slope is calculated by dividing the vertical distance by the horizontal distance between any two points of a straight line, i.e. the slope is the rate of change for the values along the line.

The equation of regression line slope:

For correct calculation the KnownYs and KnownXs series:

Should have equal number of points.
Should be non-constant.
Should contain more than three points.

Fore 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];
    y[00] := 1.6; y[05] := 2.1;
    y[01] := 1.7; y[06] := 2.2;
    y[02] := 1.8; y[07] := 2.3;
    y[03] := 1.9; y[08] := 2.4;
    y[04] := 2; y[09] := 2.8;
    x := New Double[10];
    x[00] := 2; x[05] := 6;
    x[01] := 4; x[06] := 15;
    x[02] := 2; x[07] := 17;
    x[03] := 5; x[08] := 14;
    x[04] := 12; x[09] := 3;
    st := New Statistics.Create;
    d0 := st.Slope(y, x);
    If st.Status <> 0 Then
        Debug.WriteLine(st.Errors);
    Else
        Debug.WriteLine("Tilt: " + d0.ToString);
    End If;
End Sub UserProc;

After executing the example the console window displays linear regression line tilt.

Fore.NET Example

The requirements and result of the Fore.NET example execution match with those in the Fore example.

Imports Prognoz.Platform.Interop.Stat;
…
Public Shared Sub Main(Params: StartParams);
Var
    st: Statistics;
    d0: Double;
    y, x: Array Of Double;
Begin
    y := New Double[10];
    y[00] := 1.6; y[05] := 2.1;
    y[01] := 1.7; y[06] := 2.2;
    y[02] := 1.8; y[07] := 2.3;
    y[03] := 1.9; y[08] := 2.4;
    y[04] := 2; y[09] := 2.8;
    x := New Double[10];
    x[00] := 2; x[05] := 6;
    x[01] := 4; x[06] := 15;
    x[02] := 2; x[07] := 17;
    x[03] := 5; x[08] := 14;
    x[04] := 12; x[09] := 3;
    st := New Statistics.Create();
    d0 := st.Slope(y, x);
    If st.Status <> 0 Then
        System.Diagnostics.Debug.WriteLine(st.Errors);
    Else
        System.Diagnostics.Debug.WriteLine("Tilt: " + d0.ToString());
    End If;
End Sub;