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From: Paul A Bristow (pbristow_at_[hidden])
Date: 2004-10-20 06:13:55

Sadly I was not able to attend The Redmond meeting to present proposals

but Alisdair Meredith gave the following feedback:

"I mentioned I would like feedback for stats functions, at least as a
rough indicator on how to proceed. Unfortunately feedback was
overwhelmingly negative. It is seen as a lot of work for a small
audience with minimal commercial incentive. Bill Plauger went so far as
to say given the chance again, he would not have taken on the current
math functions and once bitten, twice shy.

If this is to stand any chance of consideration, we need a cast iron case

i/ market demand
ii/ reasonable implementability

It is too early to be drawing the exhaustive list of functions.

One approach suggested was that if we got an implementation into Boost,
and there is feedback of widespread adoption, then there would be
incentive to revisit the issue."

I find this response rather baffling considering the importance of these
functions for even the most basic statistics. I can only conclude that they
are under the common delusion that computer systems are only responsible for
reproducing the data input and does not extend to deriving information to
justify action.

As a very simple example, if you make several measurements on two things,
whether racing driver lap times, pipe diameters, share prices, accident
rate, ore yield, or pollutant levels, you need some of these statistics
functions to be able to judge the probability that one is different from the

So I am now asking for your views on if it is worth producing a Boost
library version based on the existing Cephes implementation by Steven
Moshier who has kindly agreed to make it available under the Boost licence

It would be a modest effort to rename the existing Cephes C double
functions, and provide the C++ templates to use them. This would be a
'proof-of-concept' implementation, with some minimal testing (the original
code has been quite well tested).

But there would be a lot more tedious work to produce a full implementation
including all three builtin floating-point formats, and perhaps the existing
high precision UDT Floating point as well.

I am sure you will understand I would not want to put a lot of effort into
this, only to have it rejected by Boosters.

Please let me have your views on if and how to progress this topic.


Slightly updated versions of my TR2 proposal are at

Powerpoint presentation of short bullet points used in my presentation to
the UK C++

and a text version

Paul A Bristow
Prizet Farmhouse, Kendal, Cumbria UK LA8 8AB
+44 1539 561830 +44 7714 330204
mailto: pbristow_at_[hidden]

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