Remove real type

[Walter Bright]

strtr wrote:
> Walter Bright Wrote:
> 
>> strtr wrote:
>>> abcd Wrote:
>>> 
>>>> On the other hand, being an engineer, I use the reals all the
>>>> time and want them to stay. I would use the max precision
>>>> supported by the cpu then fixed precision like double any day.
>>>> 
>>>> -sk
>>> For me it's the exact opposite, reproducibility/portability is
>>> key. My problem with real is that I am always afraid my floats
>>> get upgraded to them internally somewhere/somehow.
>> With numerical work, I suggest getting the correct answer is
>> preferable <g>. Having lots of bits makes it more likely you'll get
>> the right answer. Yes, it is possible to get correct answers with
>> low precision, but it requires an expert and the techniques are
>> pretty advanced.
> 
> The funny thing is that getting the exact correct answer is not that
> big of a deal. I would give a few bits of imprecision for portability
> over x86
> 

In my experience doing numerical work, loss of a "few bits" of precision 
can have order of magnitude effects on the result. The problems is the 
accumulation of roundoff errors. Using more bits of precision is the 
easiest solution, and is often good enough.

In Java's early days, they went for portability of floating point over 
precision. Experience with this showed it to be a very wrong tradeoff, 
no matter how good it sounds. Having your program produce the crappiest, 
least accurate answer despite buying a powerful fp machine just because 
there exists some hardware somewhere that does a crappy floating point 
job is just not acceptable.

It'd be like buying a Ferrari and having it forcibly throttled back to 
VW bug performance.