[ExI] Floating-point math

[David Lubkin]

http://ubiquity.acm.org/article.cfm?id=2913029
The End of (Numeric) Error: An interview with John L. Gustafson

Walter Tichy (best-known for the Revision Control 
System) interviews computer arithmetic expert 
John Gustafson on his new format for encoding floating point.

I haven't scrutinized it closely but the concept 
makes sense. At first glance, he's taking some of 
the ideas behind recent Internet data formats and 
applying them to number-crunching.

In a nutshell, in the early decades of computing, 
each manufacturer had their own way of representing a number like

1.6025698833263803956335865659143 × 10²²³

and using it in calculations. This inconsistency 
made it very tedious to be sure that an engineer 
or scientist was getting the correct results. 
And, therefore, that planes don't crash, we have 
accurate weather forecasts, an illness is diagnosed correctly, etc.

The answer was an industry-wide standard, known 
as IEEE floating point. But the answer has a few 
problems. Gustafson discusses what's wrong and his idea for how to fix it.


-- David.