Re: [boost] [Review][PQS] Math Constants?

From: Paul A Bristow (pbristow_at_[hidden])
Date: 2006-06-05 13:28:45

Well the original zips of constants are still in the Boost vault under math
constants at

http://tinyurl.com/ryjxv 

And being MATH constants, they haven't changed ;-))

(Unlike some of the physical constants - which is why I would strongly
recommend keeping them apart, for example, by being in different
namespaces).

Disheartened by the vociferous criticism of a (the) very few reviewers,
(over use cases that I judged not important enough to reject the idea)
I have not made any changes to the method of presentation or the list.

You may find the files a convenient source of math constants that will avoid
rummaging around the web.

Nearly everyone will just want plain doubles, and one of the files in the
zip provides just that.
(floats and long doubles, are available and NTL quad_float and RR can be
handled using the macros).

C++0X Language extension proposals promise to allow one to write

  area = pi * r * r;

rather than

  area = pi() * r * r;

but I am not holding my breath.

If the PQS system is accepted and the format for constants is judged
acceptable, it may be worth taking the constants out of PQS into clearer
view so that the values may be used by those not using the full-blown units
system (for example, the mathematical and statistical functions).

However, I am coming to the view that the politically incorrect macros may
be the best way to insert the decimal digit strings into the right places in
users code.  After all, the BOOST_* namespace is pretty well polluted
already, so adding BOOST_PI, BOOST_E ... isn't going to make much difference
;-)  (Some M_PI ... values already exist from many (all?) versions of
math.h).

Other opinions?

Paul

---
Paul A Bristow
Prizet Farmhouse, Kendal, Cumbria UK LA8 8AB
[phone] & SMS, Mobile [phone] & SMS
pbristow_at_[hidden]
 
|  -----Original Message-----
|  From: boost-bounces_at_[hidden] 
|  [mailto:boost-bounces_at_[hidden]] On Behalf Of Janek Kozicki
|  Sent: 05 June 2006 15:48
|  To: boost_at_[hidden]
|  Subject: Re: [boost] [Review][PQS] Math Constants?
|  
|  Hi Paul,
|  
|  When talking about physical quantities, I'd like to ask a related
|  subject - math constants. They would be really handy inside 
|  boost (not
|  as a separate library).
|  
|  Err.. what is the status of including your math constants library ?
|  
|  PS: sorry about abrupt subject change.
|  
|  -- 
|  Janek Kozicki                                                
|           |
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