Re: Floating point problems

[PeterPeiGuo]

perldoc is very clear on this: int() simply returns the integer portion, so there is no rounding in the conventional sense.

[bluescreen]

Yeah int is very clear about that, but print isn't.

Am I asking too much if I see something prints 3 the int of that to be 3 ?

[BrowserUk]

Am I asking too much if I see something prints 3 the int of that to be 3 ?

In a word: yes.

int has a very clearly defined meaning: truncate to an integer. And that behaviour is required for many algorithms.

It never "rounds-up" as print does:

printf( "%.16f ", 3-$_ ), print 3-$_ for map 10**-$_, 1 .. 16;;
2.8999999999999999 2.9
2.9900000000000002 2.99
2.9990000000000001 2.999
2.9998999999999998 2.9999
2.9999899999999999 2.99999
2.9999989999999999 2.999999
2.9999999000000002 2.9999999
2.9999999900000001 2.99999999
2.9999999989999999 2.999999999
2.9999999999000000 2.9999999999
2.9999999999900000 2.99999999999
2.9999999999989999 2.999999999999
2.9999999999999001 2.9999999999999
2.9999999999999898 2.99999999999999
2.9999999999999991 3
3.0000000000000000 3

If you want rounding behaviour rather than truncation, use an appropriate function or module.