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Re: Discussion about accuracy modes

On Oct 13 2010, Vincent Lefevre wrote:


Note also that even with a fixed precision (or if the target
precision is specified by the user, such as in MPFR), then
"tightest" or "accurate" modes may not be practically possible:
if the range is huge (such as in MPFR or in DPE), trig functions
can't be evaluated on very large arguments in a reasonable time
and with a reasonable amount of memory.


A bad example.  Unless the arguments are totally ridiculous (i.e.
cannot occur as low powers of physical values, including such things
as the diameter of the universe measured in Planck units), they can
be.  But there are plenty of important and common functions where
there is no known method of doing so, so your point stands.

Try the error function, for a start.


Regards,
Nick Maclaren.