On 05/19/2011 03:49 PM, gregjohn wrote:
> In other words, we now have an artistic way to compare floating point error
> between different machines.

   The IEEE double-precision floating point format has 52 mantissa bits, 
and what you are seeing is hitting that limit. In other words, zooming 
any further would require more mantissa precision than that, and what 
you are seeing are the rounding errors caused by the mantissa not having 
enough bits.

   The IEEE double-precision format is pretty common in most computer 
architectures, so they will all hit the limit at the same zooming level.

   If the mandelbrot set were calculated using extended precision 
floating point numbers, which in the x87 have 64 mantissa bits, you 
could zoom a bit more (but not a lot) before hitting the artifacts.

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