Lead(Input: ITimeSeries; [Value: Integer = 1]);
Input. Variable.
Value. The parameter sets a shift (lag) of variable points in a time period.
The Lead method shifts variable backwards by the specified number of points in a time period.
The Value parameter can take only positive values; optional parameter, the default value is 1, that is, shift by one point.
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 the determinate equation method and contains at least one input variable.
Add links to the Metabase and Ms system assemblies.
Sub UserProc;
Var
Mb: IMetabase;
ModelSpace, ModelObj: IMetabaseObject;
Transf: IMsFormulaTransform;
Formula: IMsFormula;
Model: IMsModel;
Determ: IMsDeterministicTransform;
TransVar: IMsFormulaTransformVariable;
Slice: IMsFormulaTransformSlice;
TermInfo: IMsFormulaTermInfo;
Expr: IExpression;
Begin
// Get repository
Mb := MetabaseClass.Active;
// Get modeling container
ModelSpace := Mb.ItemById("MS").Bind;
// Get model
ModelObj := Mb.ItemByIdNamespace("MODEL_D", ModelSpace.Key).Edit;
Model := ModelObj As IMsModel;
// Get model calculation parameters
Transf := Model.Transform;
Formula := Transf.FormulaItem(0);
Determ := Formula.Method As IMsDeterministicTransform;
// Get the first input variable
TransVar := Transf.Inputs.Item(0);
Slice := TransVar.Slices.Item(0);
TermInfo := Transf.CreateTermInfo;
TermInfo.Slice := Slice;
// Set mode of passing variable into calculation
TermInfo.Type := MsFormulaTermType.Pointwise;
// Get model calculation expression
Expr := Determ.Expression;
Expr.References := "Ms";
// Set model calculation expression
Expr.AsString := "Lead(" + TermInfo.TermInnerText + ", 2)";
// Check if the expression is correct
If Expr.Valid
// If the expression is set correctly, save the model
Then ModelObj.Save;
// If the expression is incorrect, display a message to the console window
Else Debug.WriteLine("Model is not saved: error in the formula");
End If;
End Sub UserProc;
After executing the example the model will shift the first input variable by two points back in a time period.
Expression 1:
Lead({Brazil|BCA},2)
Result: Brazil|BCA factor observations are moved by two points back in a time period.
Use: it can be used in formulas of cross functional expression editor in any platform tool where it is available.
Expression 2:
Lead(X1,3)
Result: X1 factor points are shifted by three points back in a time period.
Use: it can be used in model formulas of modeling container.
See also: