Re: [boost] Math constants for naive and gurus? - which constants do you want?

From: Greg Colvin (gcolvin_at_[hidden])
Date: 2001-10-24 13:54:52

From: Peter Dimov <pdimov_at_[hidden]>
> From: "Noah Stein" <noah_at_[hidden]>
> > > I don't really see what's wrong with the simple
> > >
> > > namespace math
> > > {
> > >     double const pi = 3.14159265358...;
> > > }
> >
> > For me, it's an enormous burden.  I work on hardware that only supports
> > floats.  I'd have to cast the constants every time I use them.
> 
> Why?
> 
> float const pi_f = math::pi;

I think on Noah's system this will result in the value in double const pi
being converted, slowly, at runtime.

> > In addition to floats, though, I also used fixed point formats frequently,
> > so a system that supports multiple type defintions for constants is a
> great
> > thing.  I'd have almost no option but to use a runtime conversion for a
> > double constant to a fixed-point.  Maybe I'm being selfish, but I like the
> > other way.  :)
> 
> Ditto:
> 
> fixed<16, 16> const pi_x16 = math::pi;
> 
> Dynamic init may be somewhat painful at times, I admit, but you can't expect
> boost to generate the constants in every custom format, can you? It can only
> provide a common framework into which you'd fill the constants in your fixed
> point format.
> 
> What is the value of this framework?
> 
> --
> Peter Dimov
> Multi Media Ltd.
> 
> 
> Info: http://www.boost.org  Unsubscribe: <mailto:boost-unsubscribe_at_[hidden]> 
> 
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ 
> 
> 
>