Thanks to Jessica Liu for putting together the next few posts on function improvements.
In Excel 2010,
Buy Office Home And Business 2010, we made many improvements to Excel's function library. Excel 2010 will feature an accurate and consistent function library while remaining compatible with previous versions of Excel. In this first blog post,
Office 2007 Enterprise Product Key, I will be giving an overview of the work we did in this area as well as talk about the function accuracy improvements. Subsequent posts will go into the details of the consistency improvements as well as the backward compatibility story.
The first area we invested in was to improve the accuracy of functions. Over the years there have been various academic papers detailing issues in Excel's worksheet functions. In Excel 2003, we started the work to address the most serious of the issues reported in these papers and in Excel 2010 we have addressed even more of these issues. Our goal for Excel 2010 was to address the most significant function accuracy issues reported. For any function we modified, we corrected all known bugs relating to that function.
We implemented new algorithms in order to improve the accuracy of our statistical, financial and math functions. We worked very closely with industry experts to determine which algorithms to use as well as to validate these new algorithms. Our hope is that Excel 2010 users will be able to utilize functions in our library with confidence knowing that they have comparable accuracy to those of other statistical packages.
The other area we invested in was making our function library more consistent. This was in response to the other set of concerns voiced in these academic papers as well as by our users. Users have noted that there were consistency issues with Excel's function names and definitions. In Excel 2010, we will offer users a set of consistently and accurately named functions as well as function definitions that are consistent with user expectations. We have introduced over 50 new functions in order to do this.
Finally, the last piece of work we did in this area was to update the functions user interface. We have improved the function auto complete feature, and we have also made changes to support the new function set. Improved Function Accuracy
For Excel 2010, we overhauled the function library and implemented completely new algorithms for many of our statistical, financial and math functions. The Excel team partnered with Frontline Systems,
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The algorithms for calculating the follow statistical distribution functions have been modified or redesigned completely for better accuracy:
Binomial distribution
BINOMDIST, CRITBINOM
Chi squared distribution
CHIDIST, CHIINV
Exponential distribution
EXPONDIST
F distribution
FDIST, FINV
Gamma distribution
GAMMADIST,
Thomas Sabo Leather Necklace, GAMMAINV
Hypergeometric distribution
HYPGEOMDIST
Lognormal distribution
LOGNORMDIST, LOGINV
Negative Binomial distribution
NEGBINOMDIST
Normal distribution
NORMDIST, NORMINV
Standard Normal distribution
NORMSDIST, NORMSINV
Poisson distribution
POISSON
Student's t distribution
TDIST,TINV
Weibull distribution
WEIBULL
The following financial functions have improved accuracy:
Cumulative interest paid on a loan
CUMIPMT
Cumulative principal paid on a loan
CUMPRINC
Interest payment for an investment
IPMT
Internal rate of return for a series of cash flows
IRR
Payment for a loan
PMT
Payment on principal for an investment
PPMT
The accuracy of these additional functions has been improved:
Hyperbolic arcsine
ASINH
Ceiling function
CEILING
Convert function
CONVERT
Error function
ERF
Complementary error function
ERFC
Floor function
FLOOR
Natural logarithm of the gamma function
GAMMALN
Geometric mean
GEOMEAN
MOD function
MOD
Random number function
RAND
Sample standard deviation
STDEVS
Sample variation
VARS
As part of the accuracy improvements, we will also accept a larger range of input values and as a result will be returning a wider range of results for certain functions. For example, the ERF and ERFC functions will now take in negative input values, and the MOD function will be able to take larger input values.
In the next post,
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