any simple class for rational numbers?

[Leslaw Bieniasz]

Hi,

I need a simple class implementing rational numbers
as fractions of integers, together with arithmetic
operations on such fractions, checks for overflow, etc.
Any suggestions?

L.B.


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[Hans Mull]

Hi,

I need a simple class implementing rational numbers
as fractions of integers, together with arithmetic
operations on such fractions, checks for overflow, etc.
Any suggestions?

L.B.


!!! PLEASE NOTE MY NEW ADDRESS SINCE January 1st, 2008, INDICATED BELOW !!!
*-------------------------------------------------------------------*
| Dr. Leslaw Bieniasz, |
| Institute of Physical Chemistry of the Polish Academy of Sciences,|
| Department of Complex Systems and Chemical |
| Processing of Information |
| ul. Niezapominajek 8, 30-239 Cracow, Poland. |
| tel. (personal) +48 (12) 6395212 |
| tel./fax. (secretariat) +48 (12) 4251923 |
| E-mail: (e-mail address removed) |
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| Interested in Computational Electrochemistry? |
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I don't know if you think this is simple, but I worked with GMP some
time ago. mpq_t is a rational number class.

Kind regards

 

[Juha Nieminen]

I need a simple class implementing rational numbers
as fractions of integers, together with arithmetic
operations on such fractions, checks for overflow, etc.
Any suggestions?

I think that in the time it took you to write this and the time it
will take for someone to write an useful answer, you could have written
such a simple class yourself...

 

[Hans Mull]

I think that in the time it took you to write this and the time it
will take for someone to write an useful answer, you could have written
such a simple class yourself...

Maybe he has some special requirements, like a very efficient libary or
arbitrary precision support...

 

[shazled]

I need a simple class implementing rational numbers
as fractions of integers, together with arithmetic
operations on such fractions, checks for overflow, etc.
Any suggestions?

I haven't used it myself, but boost provides one that seems to fit
your requirements:
http://www.boost.org/libs/rational/index.html

Saul

 

[Christopher Dearlove]

I think that in the time it took you to write this and the time it
will take for someone to write an useful answer, you could have written
such a simple class yourself...

From past conversation with the author of the Boost Rational class (which
I have however never used) I know that there's more to it than that. Just
to take one detail, you probably want to store it in simplest form (e.g. 3/4
rather than 6/8) which reduces the chances of overflow when using finite
length integers. In fact you want to do some such manipulation during,
say, addition so that you don't overflow when you don't have to, even if a
naive implementation might. (It's possible for two numbers to be safe, their
sum to be safe, but the obvious implementation to overflow during the
calculation. I don't know if t's always possible to avoid that.) And of
course you want to do that efficiently (no more often than necessary). I
don't know all the details. I understand that, as ever, Knuth is the
starting
point.

 

[Juha Nieminen]

From past conversation with the author of the Boost Rational class (which
I have however never used) I know that there's more to it than that. Just
to take one detail, you probably want to store it in simplest form (e.g. 3/4
rather than 6/8) which reduces the chances of overflow when using finite
length integers. In fact you want to do some such manipulation during,
say, addition so that you don't overflow when you don't have to, even if a
naive implementation might. (It's possible for two numbers to be safe, their
sum to be safe, but the obvious implementation to overflow during the
calculation. I don't know if t's always possible to avoid that.) And of
course you want to do that efficiently (no more often than necessary). I
don't know all the details. I understand that, as ever, Knuth is the
starting
point.

It was just a joke.