“Undefined time” above refers to columns beyond the time horizon of the model- rather an ethereal definition.

Dennis

As for LOOKUP functions, one of the greatest advances in computing was databases, and one key strength of databases is using text to identify records. Many tables are indexed best by text rather than numbers, meaning referring to values in tables is often best accomplished using LOOKUP functions rather than INDEX.

Finally, NPV. Maybe those of us who’ve been around since Lotus 123 was the leading spreadsheet just know to use NPV(r,…)*(1+r) and do so automatically, but there’s a huge advantage to NPV which also bears on ROUND: cell formulas, especially long chains of discounted cashflow calculations, are subject to double precision rounding errors (akin to represeting 1/3 + 1/3 + 1/3 to any FINITE number of decimal places, the text representation of results will never add up to 1.0). NPV is also subject to rounding errors, but because all intermediate calculations are performed in FPU hardware and intermediate results stored in 80-bit FPU registers rather than 64-bit cell values, NPV avoids the off-by-a-bit results that are pretty much guaranteed by calculating net present values without any functions. Were the FAST authors ever trained in or have any practical experience with rounding errors due to finite precision in computer calculations? Any of them ever subscribe to any IEEE or SIAM publication?

A workbook is a set of inter-dependent worksheets, where data is structured along two axes of presentation; essentially a highly structured spreadsheet. In a financial model, time is usually the primary (horizontal) axis with the vertical axis setting out various calculatory themes.

Regards

Paula

I have a question – is there a definition for “undefined time” (FAST-2.01-08.1), becuase I don’t fully understand what it means.

Thanks,

Valentina