Log(Input: Variant; Base: Variant): Variant;
Input. Variable.
Base. Base of logarithm.
The Log method returns the logarithm of specified variable points by assigned base.
NOTE. The point value, for which the logarithm is found, and its base must be greater than zero.
Executing the example requires that the repository contains a modeling container with the MS identifier. This container includes a model with the MODEL_D identifier that is calculated by method of determinate equation and containing more than one input variable.
Sub UserProc;
Var
Mb: IMetabase;
ModelSpace, ModelObj: IMetabaseObject;
Transf: IMsFormulaTransform;
Formula: IMsFormula;
Model: IMsModel;
Determ: IMsDeterministicTransform;
TransVar: IMsFormulaTransformVariable;
Slice: IMsFormulaTransformSlice;
TermInfo: IMsFormulaTermInfo;
Inp_1, Inp_2: String;
Expr: IExpression;
Begin
Mb := MetabaseClass.Active;
ModelSpace := Mb.ItemById("MS").Bind;
ModelObj := Mb.ItemByIdNamespace("MODEL_D", ModelSpace.Key).Edit;
Model := ModelObj As IMsModel;
Transf := Model.Transform;
Formula := Transf.FormulaItem(0);
Determ := Formula.Method As IMsDeterministicTransform;
TransVar := Transf.Inputs.Item(0);
Slice := TransVar.Slices.Item(0);
TermInfo := Transf.CreateTermInfo;
TermInfo.Slice := Slice;
TermInfo.Type := MsFormulaTermType.Pointwise;
Inp_1 := TermInfo.TermInnerText;
TransVar := Transf.Inputs.Item(1);
Slice := TransVar.Slices.Item(0);
TermInfo := Transf.CreateTermInfo;
TermInfo.Slice := Slice;
TermInfo.Type := MsFormulaTermType.Pointwise;
Inp_2 := TermInfo.TermInnerText;
Expr := Determ.Expression;
Expr.References := "Ms";
Expr.AsString := "Log(" + Inp_1 + ", " + Inp_2 + ")";
If Expr.Valid
Then ModelObj.Save;
Else Debug.WriteLine(The model is not saved: error in the formula);
End If;
End Sub UserProc;
After executing the example the model calculates logarithm of the first input variable points by the base set by appropriate points of the second input variable.
Expression 1:
Log({Brazil|BCA},2)
Result: the logarithm of Brazil|BCA factor observations is calculated by the base of 2.
Use: it can be used in formulas of calculated series of time series database and model formulas of modeling container that is a child of the time series database.
Expression 2:
Log(X1,5)
Result: the logarithm of X1 factor points is calculated by the base of 5.
Use: it can be used in model formulas of modeling container.
Expression 3:
Log(10,2)
Result: log210 = 3.32.
Use: it can be used in formulas of calculated series of time series database and modeling container models.
See also: