On Thu, Oct 31, 2002 at 03:18:47PM -0700, M. Warner Losh wrote: > In message: <[EMAIL PROTECTED]> > Terry Lambert <[EMAIL PROTECTED]> writes: > : > Nope. The only difference between 53 bits and 64 bits of precision is > : > just that: precision. The number of bits for expoentent is > : > independent of this. > : > : .125 ^ 2 = 0.015625 > : .25 ^ 3 = 0.015625 > : > : So if I go from 3 digits of precision to 2 digits of precision for > : my mantissa, in order to represent the same number, I need a larger > : exponent. > > That's not how it works. The exponent is more like > > .1250000 * 2^3 > vs > .1249999 * 2^3 > > Both have exponent 3, but the differ by a bit or two in the mantissa. >
Loren already posted a pointer to "What Every Scientist Should Know About Floating-Point Arithmetic" by David Goldberg. But, for Terry edification http://cch.loria.fr/documentation/IEEE754/ACM/goldberg.pdf This is only 1 of 66100 hits from a google search with keywords "floating point scientist". -- Steve To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message
