Smooth

Syntax

Smooth (Year1, Value1, Year2, Value2,... YearN, ValueN) or
Smooth (ExcelFilename, ExcelRangeName)

Description

Estimates a value in any given intermediate year based on the year/value pairs specified in the function and a smooth curve polynomial function of the form

Y = a + b.X + c. X2 + d. X3 + e.X4 + ...

When more points are available, a higher degree polynomial is used to give a more accurate fit.

NB: A minimum of 4 year/value pairs are required in order for the curve to be estimated.

Using the above two alternatives syntaxes year/value pairs can either be entered explicitly or linked to a range in an Excel spreadsheet. Use the Yearly Time-series Wizard to input these values or to specify the Excel data. In either case, years do not need to be in any particular order, but duplicate years are not allowed, and must be in the range 1990-2200.

When linking to a range in Excel, you specify the full pathname of a valid Excel worksheet or spreadsheet (an XLS or XLW) file, followed by a valid Excel range. A range can be either a valid named range (e.g. "Import") or a range address (e.g. "Sheet1!A1:B5"). The Excel range must contain pairs of years and values in its cells arranged into 2 columns. Use the WEAP Yearly Time-series Wizard to select a worksheet, to choose among the valid named ranges in the worksheet, and to preview the data that will be imported.

NB: The Current Accounts value is always implicit in the function, and will override any value explicitly entered for that year by the user. So for example, if the Current Accounts year is 1997 and the Current Accounts value (entered in Current Accounts) is 200.0 then the above function will results in the value 200.0 for both 1998 and 1999.

Tip

Use the Yearly Time-Series Wizard to enter the data for this function.