jralls at ceridwen.us
Sun May 25 10:34:14 EDT 2014
On 25 May 2014, at 07:19, John Ralls <jralls at ceridwen.us> wrote:
> On 25 May 2014, at 01:54, Christian Stimming (mobil) <christian at cstimming.de> wrote:
>> Thanks for starting the discussion.
>> If we've reached the point where our int64 rational numbers do not fit our problem requirements anymore, I'd rather look for a different number representation that fits our application domain better. I'm thinking about replacing rational numbers by decimal floating point numbers. That is, a number is represented by m * 10^e with the mantissa m and exponent e as signed integers. This is different from our normal *binary* floating point in that we use the exponent with base 10. However, all common rules for floating point can be applied just as normal. By the way, maybe there is even a standard comparable to IEEE 754 available?
>> Just another possible way to proceed for solving this problem...
> Is this http://en.wikipedia.org/wiki/Decimal_floating_point what you're talking about? If so, it says that the IEEE spec is 854, and answers some of my questions, but leaves out database support.
A different spec: http://speleotrove.com/decimal/decarith.html
And an implementation, which is used in CPython: http://www.bytereef.org/mpdecimal/index.html
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