Handling big FP numbers

Murilo murilomiranda92 at hotmail.com
Sat Feb 9 03:33:13 UTC 2019


On Saturday, 9 February 2019 at 03:28:24 UTC, Adam D. Ruppe wrote:
> On Saturday, 9 February 2019 at 03:21:51 UTC, Murilo wrote:
>> Now, changing a little bit the subject. All FPs in D turn out 
>> to be printed differently than they are in C and in C it comes 
>> out a little more precise than in D. Is this really supposed 
>> to happen?
>
> Like I said in my first message, the D default rounds off more 
> than the C default. This usually results in more readable stuff 
> - the extra noise at the end is not that helpful in most cases.
>
> But you can change this with the format specifiers (use 
> `writefln` instead of `writeln` and give a precision argument) 
> or, of course, you can use the same C printf function from D.

Thanks but here is the situation, I use printf("%.20f", 0.1); in 
both C and D, C returns 0.10000000000000000555 whereas D returns 
0.10000000000000001000. So I understand your point, D rounds off 
more, but that causes loss of precision, isn't that something bad 
if you are working with math and physics for example?


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