
 Rate Projections Functions Walkthrough
 Accruals and Cash
 Repeating Formulae
 Range Names and References
 Optional Parameters
 Using PmtsPerYear
 Modelling Seasonality
 Calculating Interest
 Using Business Functions in VBA (Visual Basic for Applications)
 Array Functions
 Volatility
 Annual Equivalent Rates
 Array Function
 Auto Multi Functions
 Variable Plurality
 GoalSeek
 Where a Business Function can also be an array function, the "arrayness" comes in the first argument, which usually a date. So a range of dates as the input argument results in a range of results returned from the function, one for each date or time period.
 Excel uses the ControlShiftEnter key combination as practically the only support you get for array functions. You enter an array function by selecting a range, typing the formula in the formula pane and pressing ControlShiftEnter. It"s the same process for editing. Thereafter what you have to remember is that Excel treats the array region as a single entity that you cannot change part (e.g. a cell) of. Don"t think you can type curly brackets ({}) to make an array function either  it doesn"t work because array formulas are actually stored within Excel in an entirely different way to "normal" formulas.
 When you"ve got a long argument list to complete, you might not want to go straight away to the array form of he function. In fact, we"d recommend that you first of all use the "normal" version of the function, then the "normal" version with a range of inputs (which returns the first result in the return range), and only then convert that function to an array function over the selected range.
 For the step of converting a single function in a cell to a range, use the "Expand Array Function" utility. This will place an array formula in all the cells of the selected range, where the array formula is the formula in the topleft cell of the range in question. So it essentially expands a single cell"s "normal" function to a fully fledged array formula.
 If you select a 2dimensional arrays, the utility will ask you a question about how you want the formulae expanded. It will ask whether you want the formula expanded to the right, whether you wanted it expanded down, or whether you want in expanded both down and right. This is useful for "arraying a whole column of different formulae over a range of columns in your timebase (the same applies to a whole row over the rows in your timebase too).
 This is the reverse of "Expand Array Function".
 You select a range and the utility will concert the array formulae in that range to single cell "normal" formulae.
 The resulting "normal" formulae will be created either in the leftmost column or the topmost row, depending on the context. The utility decides whether your "context" is horizontal (array formulas along rows), or vertical (in columns) by inspecting the first two array formulae in the first row and column and seeing if they are identical.
Array Function Tools  
Ways of working with array functions  
Because a lot of BF"s projections functions can also be used as array functions, we "ve supplied a couple of tools to help in their usage. To recap on array functions: The two utilities we"ve provided are: 1. Expand Array Function 2. Collapse Array Function Note that neither of these two utilities currently have an undo facility. 