On 2007-05-08, Greg Corradini <gr***********@gmail.comwrote:

I'm running descriptive stats on mileages from a database

(float numbers, about a million records). My sum returns

1.#QNAN, which I understand from searching this forum is an

error.

Not necessarily. You've ended up with a floating point "not a

number" value (AKA a NaN). That might or might not be an

error. Whether it's an error not not depends on your input

data and your algorithm.

While I'm looking for help in solving this problem, I'm more

interested in a general explanation about the cause of this

problem.

If you're asking how you end up with a NaN, there are several

ways to generate a NaN:

0/0

Inf*0

Inf/Inf

Inf-Inf

Almost any operation on a NaN

http://en.wikipedia.org/wiki/NaN http://steve.hollasch.net/cgindex/coding/ieeefloat.html
--

Grant Edwards grante Yow! Spreading peanut

at butter reminds me of

visi.com opera!! I wonder why?