ISmNonLinearEquations.InitExpression

Syntax

InitExpression: Integer;

Description

The InitExpression method checks if entered variables and equations without executing statistical method are correct.

Comments

If input parameters are set correctly, the 0 value is returned, otherwise error code is returned, which can be seen by means of the IStatMethod.ErrorByStatus property.

Example

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

Sub UserProc;
Var
    Eqs: ISmNonLinearEquations;
    Funcs: Array[0..2] Of String;
    inits: Array[0..2] Of Double;
Begin
    Eqs := New SmNonLinearEquations.Create;
    funcs[0] := "X1-22+0.5*X2-X3";
    funcs[1] := "X2-26.5+2*X1+0.5*X3";
    funcs[2] := "X3+9-X1+6*X2";
    Eqs.Functions := Funcs;
    Eqs.CoefficientsOrder := "X1;X2";
    Eqs.CalcInitExpressionMode := CalcInitExpressionType.Manual;
    inits[0] := 10; //x1
    inits[1] := 7; //x2
    inits[2] := -1; //x3
    Eqs.InitApproximation := inits;
    Eqs.MethodType := NonLinearEquationsType.MinErrorGaussNewtonMethod;
    Eqs.Tolerance := 0.0001;
    Debug.WriteLine("Error code: " + Eqs.InitExpression.ToString);
    Debug.WriteLine(Eqs.ErrorByStatus(Eqs.InitExpression));
End Sub UserProc;

After executing the example the console window displays error code and text:

Error code: 102

Error 102: The number of initial approximations is not equal to the number of coefficients