Re^2: floating point addition

I think bignum just gives you more precision but does not eliminate the problem.

To eliminate the problem you could use bigrat and use fractions.

Compare:

perl -Mbignum -e ' printf "%20.17f\n", 20.1;'
20.10000000000000142

perl -Mbigrat -e ' printf "%20.17f\n", 20.1;'
20.10000000000000142

perl -Mbigrat -e ' printf "%20.17f\n", 20+1/10;
20.00000000000000000
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Re^3: floating point addition by choroba (Cardinal) on Jan 12, 2015 at 18:09 UTC
You are right about bignum. Your bigrat example, though, doesn't work. One needs `perl -Mbigrat -le 'print 20/1 + 1/10'` [download] لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ	[reply] [d/l]
Re^4: floating point addition by morgon (Priest) on Jan 12, 2015 at 20:15 UTC
`perl -Mbigrat -e ' printf "%20.17f\n", 20/1+1/10;' 20.10000000000000142 perl -Mbigrat -e ' printf "%20.17f\n", 201/10;' 20.10000000000000142` [download] Does not seem to work either - I don't know why not...	[reply] [d/l]
Re^5: floating point addition by choroba (Cardinal) on Jan 12, 2015 at 22:49 UTC
Because `%f` converts the Math::BigRat object to "a floating-point number, in fixed decimal notation" (sprintf). لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ	[reply] [d/l]
Re^6: floating point addition by morgon (Priest) on Jan 13, 2015 at 01:34 UTC
Re^7: floating point addition by choroba (Cardinal) on Jan 13, 2015 at 08:39 UTC