Re: [boost] OT Query: Robert G. Burger and R. Kent Dybvig, "Printing Floating-Point Numbers Quickly and Accurately"

From: Paul A Bristow (pbristow_at_[hidden])
Date: 2006-03-08 04:38:09

| -----Original Message-----
| From: boost-bounces_at_[hidden] 
| [mailto:boost-bounces_at_[hidden]] On Behalf Of Stefan Slapeta
| Sent: 26 February 2006 15:12
| To: boost_at_[hidden]
| Subject: Re: [boost] OT Query: Robert G. Burger and R. Kent 
| Dybvig, "Printing Floating-Point Numbers Quickly and Accurately"
| 
| Paul A Bristow wrote:
| > Sorry for an Off-topic question, but does anyone know of a C/C++
| > Implementation of a C++ algorithm based on the paper by
| > Robert G. Burger and R. Kent Dybvig, entitled:
| > "Printing Floating-Point Numbers Quickly and Accurately"
| > http://portal.acm.org/citation.cfm?doid=989393.989430  ACM 
| subscribers only
| > 
| http://citeseer.ist.psu.edu/cache/papers/cs/2654/http:zSzzSzww
| w.cs.indiana.e
| > 
| duzSz~burgerzSzFP-Printing-PLDI96.pdf/printing-floating-point-
| numbers.pdf
| > 
| 
| For me that's not completely off-topic as I always wished boost could 
| provide this algorithms one day :-) However, I'm not really 
| an expert in 
| this field so I never started working on it.
| 
| Nevertheless, there is an earlier paper by David Gay from 
| 1990 for which 
| an implementation exists. AFAIK Mozilla's JavaScript 
| implementation also 
| uses a java port of it. Although I have downloaded Burger's paper 
| (published in 1996, IIRC) once, I never investigated what's 
| different/improved there.
| 
| Gay's implementation can be found both at
| http://www.netlib.org/fp/index.html
| and
| http://citeseer.nj.nec.com/gay90correctly.html
| (seems to be down at the moment).

Thanks for this info - which I have yet to study in detail  - still
recovering from a recent successful ascent of Uhuru on Kilimanjaro, the Roof
of Africa :-)))

Burger and Dybvig claim their method is MUCH (70x) faster (avoids explicit
expensive use of rational arithmetic). And it gives explicit control of
rounding. But I have yet to get it to work, no doubt due to my lack of
brain.  

Thank you.

Paul

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Paul A Bristow
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