IMsNonLinearEquationsTransform.DerivativeShift

Syntax

DerivativeShift: Double;

Description

The DerivativeShift property determines the increment of an argument (%) for calculating partial derivatives required for the Newton method.

Example

Executing the example requires a modeling container with the CONT_MODEL identifier and a model of the System of Non-linear Equations type with the NON_LINEAR identifier.

Sub main;

Var

ActiveMetabase: IMetabase;

ModelCont: IMetabaseObjectDescriptor;

Descript: IMetabaseObjectDescriptor;

Obj: IMetabaseObject;

Model: IMsModel;

Eq: IMsNonLinearEquationsTransform;

Transform: IMsFormulaTransform;

Begin

ActiveMetabase := MetabaseClass.Active;

ModelCont := ActiveMetabase.ItemById("CONT_MODEL");

Descript := ActiveMetabase.ItemByIdNamespace("NON_LINEAR", ModelCont.Key);

Obj := Descript.Edit;

Model := Obj As IMsModel;

Model.TreatNullsAsZeros := True;

Transform := Model.Transform;

Eq := Transform.EquationsFormula.Method As IMsNonLinearEquationsTransform;

Eq.MethodType := NonLinearEquationsType.NewtonMethod;

Eq.DerivativeShift := 2.1;

Obj.Save;

End Sub main;

After executing the example, the Newton method is set as a calculation method of non-linear equation system, the argument increment is set equal to 2.1.