kahan

It's unfortunate that Intel didn't consult Kahan earlier in the design process of the 8087, when they could have designed a base 10 floating point unit, as recommended by Kahan.

There's an algorithm to deal with this kind of additive small error, the Kahan Summation algorithm.

(to the point of making a pilgrimage to visit Kahan early on) What does that mean?

The number of people who add up arrays of floating point numbers and don't know about Kahan summation is really incredible.

The Julia developers have paid fastidious attention to correctness (to the point of making a pilgrimage to visit Kahan early on).

William Kahan earlier in their design of the x87 floating point unit.

William Kahan who was instrumental in the Intel 8087 was about 45.

Don't tell them about Kahan summation--they'll freak out and go rewrite everything.

In fact, I seem to remember a Kahan article saying that binary was superior to all other bases that could be considered for floating-point.

William Kahan argues better than I can [1][2].

When we got the chance to ask him about it, Kahan was quite negative about interval arithmetic, noting that intervals tend to grow exponentially large as your computation progresses.

No thanks, I will stick with the amazingly successful, ubiquitous, thoroughly thought out standard, that was spearheaded by William Kahan – one of the greatest numerical analysts of all time.

It also messes with implementations of "log1p", Kahan summation, and other high-precision algorithms like double-double arithmetic.

Do you have a source for “they could have designed a base 10 floating point unit, as recommended by Kahan”?

The original designer's commentary about it is: William Kahan, "Branch Cuts for Complex Elementary Functions, or Much Ado About Nothing's Sign Bit", in The State of the Art in Numerical Analysis (eds.

It is not in the article being discussed (only one occurrence of “decimal”), and I have a hard time believing that Kahan didn't believe that binary was the superior base and should be implemented first (and is so efficient that it should be implemented even if one builds a decimal system too).

But it's quite dense and seems to require (at least for me) Kahan's speech to get all the nuances.

I do think that Kahan's objections to Java's floating-point support were more than just philosophical, although it's unclear to me at this point how many of them still apply.