WorksheetFunction.Forecast_Linear method (Excel)
Calculates, or predicts, a future value by using existing values. The predicted value is a y-value for a given x-value. The known values are existing x-values and y-values, and the new value is predicted by using linear regression. Use this function to predict future sales, inventory requirements, or consumer trends.
Syntax
expression.Forecast_Linear (Arg1, Arg2, Arg3)
expression A variable that represents a WorksheetFunction object.
Parameters
| Name | Required/Optional | Data type | Description |
|---|---|---|---|
| Arg1 | Required | Double | x - the data point for which you want to predict a value. |
| Arg2 | Required | Variant | known_y's - the dependent array or range of data. |
| Arg3 | Required | Variant | known_x's - the independent array or range of data. |
Return value
Double
Remarks
If x is nonnumeric, Forecast_Linear returns the #VALUE! error value.
If known_y and known_x parameters are empty or contain a different number of data points, Forecast_Linear returns the #N/A error value.
If the variance of known_x parameters equals zero, Forecast_Linear returns the #DIV/0! error value.
The equation for Forecast_Linear is a+bx, where 
and 
and where x and y are the sample means AVERAGE(all known_x) and AVERAGE(all known_y).
Example
Dim instance As WorksheetFunction
Dim Arg1 As Double
Dim Arg2 As Object
Dim Arg3 As Object
Dim returnValue As Double
returnValue = instance.Forecast_Linear(Arg1, Arg2, Arg3)
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