floating point comparison basics

[ed]

On Wednesday, 4 December 2013 at 01:52:09 UTC, bearophile wrote:
> H. S. Teoh:
>
>> The first rule of floating-point comparisons is that you never 
>> use ==.
>
> So I suggested to disallow the == among FP numbers in D (and 
> allow FP comparisons with "is" or with specialized functions, 
> including one function that does what == does today).
>
>
> For the original poster, for general FP comparisons I suggest 
> std.math.feqrel, it's not fast, it's not const-correct, but 
> it's good.
>
> Bye,
> bearophile

Thanks, I will look into it.

I've implemented my comparison function and it gives the same 
results as approxEquals ... yay! ...only took me several hours to 
achieve about 10 LOC but I finally understand it

Cheers,
Ed