[erlang-questions] Any way to correct the round off errors?

[Richard Kelsall]

Witold Baryluk wrote:
>> so we probably shouldn't trust more than 12 digits of precision because
>> each calculation will lose some precision from the end of the number.
> Substraction (and addition) can lose  any number of digits you wish.
> 
I would be horrified if I added two doubles

0.111111111111 +
0.111111111111

and got

0.225745048327

I have no idea what the IEEE standard specifies, but I can't imagine
anybody ever implementing or using a version that gave this answer.
I would expect at least twelve significant digits of precision.

0.2222222222228765767

But if I added these two doubles

0.111111111111 +
0.000000000000111111111111

I wouldn't be surprised to get

0.111111111111343786587698

which gives the right answer to 12 significant digits, but loses all
of the significant digits in the second number.The same for subtraction.


Richard.