On May 21, 11:27 pm, Dave Parker <[EMAIL PROTECTED]> wrote: > On May 21, 7:01 pm, Carl Banks <[EMAIL PROTECTED]> wrote: > > > The crucial thing is not to slow down the calculations with useless > > bells and whistles. > > Are you running your simulations on a system that does or does not > support the "useless bell and whistle" of correct rounding? If not, > how do you prevent regression towards 0?
The "useless bell and whistle" is switching to multiprecision. I'm not sure whether our hardware has a rounding bias or not but I doubt it would matter if it did. > For example, one of the things that caused the PS3 to be in 3rd place > behind the Wii and XBox 360 is that to save a cycle or two, the PS3 > cell core does not support rounding of single precision results -- it > truncates them towards 0. That led to horrible single-pixel errors in > the early demos I saw, which in term helped contribute to game release > delays, which has turned into a major disappointment for Sony. And you believe that automatically detecting rounding errors and switching to multi-precision in software would have saved Sony all this? Carl Banks -- http://mail.python.org/mailman/listinfo/python-list