Re: Parsing timestamps?

Am 16.07.2025 um 18:23 schrieb Anton Ertl:

minforth <minforth@gmx.net> writes:

Am 16.07.2025 um 13:25 schrieb Anton Ertl:

I did not do any accuracy measurements, but I did performance
measurements

YMMV but "fast but wrong" would not be my goal.  ;-)

 I did test correctness with cases where roundoff errors do not play a
role.
 As mentioned, the RECursive balanced-tree sum (which is also the
fastest on several systems and absolutely) is expected to be more
accurate in those cases where roundoff errors do play a role.  But if
you care about that, better design a test and test it yourself.  It
will be interesting to see how you find out which result is more
accurate when they differ.

Meanwhile many years ago, comparative tests were carried out with a
couple of representative archived serial data (~50k samples) by
using a Java 128-bit quadruple fp-math class to perform summations
and calculate dot-product results.
The results were compared with those of naive linear summation and
multiplication and pairwise divide&conquer summation at different
rounding modes, for float32 and float64. Ultimately, Kahan summation
was the winner. It is slow, but there were no in-the-loop
requirements, so for a background task, Kahan was fast enough.