IModelling.Ratio

Syntax

Ratio(Input: ITimeSeries;

[Period: MsInversionLag = 0;]

[PeriodNumber: Integer = 1]): Variant;

Parameters

Input. Output variable.

Period. Period, relative to which the growth coefficient is calculated.

PeriodNumber. Period lag.

Description

The Ratio method calculates growth coefficient for variable points.

Comments

Features of setting parameters:

Period. Optional parameter. The default value - MsInversionLag.PrecidingValue (previous period).
PeriodNumber. Optional parameter. Minimum and default value is 1.

Example

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 using the determinate equation method and contains at least one input variable.

Add links to the Metabase and Ms system assemblies.

Sub UserNvl;
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 := "Ratio(" + TermInfo.TermInnerText + ", MsInversionLag.PrecidingValue, 1)";
    // 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 UserNvl;

After executing the example the model will calculate growth coefficient of the first input variable points to the previous period.

Example of Use in Expressions

Expression 1:

Ratio({Brazil|BCA},MsInversionLag.PrecidingYear)

Result: the growth coefficient of observation values to the corresponding period of the previous year will e calculated for the Brazil|BCA factor.

Use: it can be used in formulas of cross functional expression editor in any platform tool where it is available.

Expression 2:

Ratio(X1,MsInversionLag.PrecidingValue,2)

Result: the growth coefficient of point values to the period shifted from the current one by two points will be calculated for the X1 factor.

Use: it can be used in model formulas of modeling container.