[sac-user] print function alternatives?

Raphael 'kena' Poss r.c.poss at uva.nl
Mon Aug 2 20:01:29 CEST 2010

Hi all,

Op 2 aug 2010, om 18:45 heeft Robert Bernecky het volgende geschreven:
> In particular, it still uses printf() [...]
> My intent was to make it use a precise formatter, such
> as that proposed in "Printing Floating-Point Numbers Quickly and Accurately", by Robert G. Burger and R. Kent Dybvig.

For your information, many open-source Unices nowadays use the gdtoa library by D. Gay from netlib: http://www.netlib.org/fp/gdtoa.tgz

This uses concepts and algorithms from

T. J. Dekker, "A Floating-Point Technique for Extending the
Available Precision", Numer. Math. 18 (1971), pp. 224-242


"How to Print Floating-Point Numbers Accurately" by
Guy L. Steele, Jr. and Jon L. White [Proc. ACM SIGPLAN '90, pp. 112-126].

As far as precision goes, this is formally specified. I don't know how it compares to the techniques in Burger & Dybvig, actually.

As an option, is it possible to output floats in hexadecimal? This should prevent rounding errors.

Raphael 'kena' Poss · r.c.poss at uva.nl · +31 20 525 7559
UvA · FNWI · IvI · CSA · 1098XG 107 Amsterdam (NL)
Real computer scientists despise the idea of actual hardware.  Hardware has
limitations, software doesn't.  It's a real shame that Turing machines are
so poor at I/O.

More information about the sac-user mailing list