- From: Boris Zbarsky <bzbarsky@mit.edu>
- Date: Thu, 04 Sep 2014 10:08:58 -0400
- To: public-fx@w3.org
On 9/4/14, 9:42 AM, Tab Atkins Jr. wrote: > Inverting a matrix is a well-defined operation When operating on real numbers. Sadly, computers typically operate on IEEE floats/doubles, not on real numbers. And with those, the result can depend strikingly on the exact algorithm used to compute the inverse, especially for near-singular matrices. > which similarly had a unique and well-defined solution (but the simple algorithm wasn't > obvious). There is no such thing as "unique and well-defined solution" when dealing with floating point, unless you fix the algorithm. And I mean _really_ fix. For example, floating point addition is not associative, and floating point multiplication does not distribute over floating point addition, so you have to be very careful when defining floating point algorithms if you really want them to produce the same output in multiple implementations. -Boris
Received on Thursday, 4 September 2014 14:09:29 UTC