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*Subject*: **ODD{F,L}, Yield and Price spreadsheet functions.**

*From*:**robert_weir@us.ibm.com***To*: office@lists.oasis-open.org*Date*: Wed, 14 May 2008 18:07:17 -0400

I had an action item to see if OOXML has good definitions for ODD{F,L}, Yield and Price spreadsheet functions.

The final OOXML text is not available publicly, or even to JTC1 or SC34 participants, but I happened upon a copy, and what I'll report is based on this text of April 30th.

The two functions ODDFPRICE and ODDLYIELD have full definitions, including a formula. I have no idea whether this formula is correct (from a financial perspective) or whether it in fact reflects Microsoft Excel's calculations.

For example, ODDLYIELD is defined as:

ODDFYIELD and ODDLPRICE had useless definitions. They just said something like "Computes the price per $100 face value of a security having an odd (short or long) last coupon period", with no formula or reference given.

To move forward on this we need to consider three possibly different definitions of any spreadsheet function:

1) The correct formula, as determined by an external authority, perhaps another standard, or a standard textbook or handbook in the field.

2) What Excel calculates. This may differ in some cases with the external authority, for example with leap year calculations, or the definition of the CEILING function.

3) The formula that OOXML provides. We should not assume that this formula accurately reflects what Excel actually does. In fact, using these definitions as a short cut to our own definitions is likely to lead us astray.

I'll drill down more into these financial functions. I've ordered some books on financial mathematics that should explain these and other mysteries of life.

-Rob

___________________________

Rob Weir

Software Architect

Workplace, Portal and Collaboration Software

IBM Software Group

email: robert_weir@us.ibm.com

phone: 1-978-399-7122

blog: http://www.robweir.com/blog/

**Follow-Ups**:**Re: [office] ODD{F,L}, Yield and Price spreadsheet functions.***From:*"David A. Wheeler" <dwheeler@dwheeler.com>

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