File: gawk.info,  Node: FP Math Caution,  Next: Arbitrary Precision Integers,  Prev: MPFR features,  Up: Arbitrary Precision Arithmetic

16.4 Floating-Point Arithmetic: Caveat Emptor!
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     Math class is tough!
                   -- _Teen Talk Barbie, July 1992_

   This minor node provides a high-level overview of the issues involved
when doing lots of floating-point arithmetic.(1)  The discussion applies
to both hardware and arbitrary-precision floating-point arithmetic.

     CAUTION: The material here is purposely general.  If you need to do
     serious computer arithmetic, you should do some research first, and
     not rely just on what we tell you.

* Menu:

* Inexactness of computations:: Floating point math is not exact.
* Getting Accuracy::            Getting more accuracy takes some work.
* Try To Round::                Add digits and round.
* Setting precision::           How to set the precision.
* Setting the rounding mode::   How to set the rounding mode.

   ---------- Footnotes ----------

   (1) There is a very nice paper on floating-point arithmetic
(http://www.validlab.com/goldberg/paper.pdf) by David Goldberg, "What
Every Computer Scientist Should Know About Floating-Point Arithmetic,"
'ACM Computing Surveys' *23*, 1 (1991-03): 5-48.  This is worth reading
if you are interested in the details, but it does require a background
in computer science.