The issue is that floating point numbers are really not precise. This is not inherent to Haskell in particular - any given computer (and programming language) is subject to lack of precision for floating point numbers. You can take a look at the wikipedia entry (http://en.wikipedia.org/wiki/Floating_point_numbers). If you want a really "meaty" description of the issues involved, take a look at Knuth's "Seminumerical Algorithms". On Feb 5, 2013, at 4:41 PM, yi lu wrote:
Hi,
I found that in ghci, I input [0.1,0.2..2] and run, I get a result of
[0.1,0.2,0.30000000000000004,0.4000000000000001,0.5000000000000001,0.6000000000000001,0.7000000000000001,0.8,0.9,1.0,1.1,1.2000000000000002,1.3000000000000003,1.4000000000000004,1.5000000000000004,1.6000000000000005,1.7000000000000006,1.8000000000000007,1.9000000000000008,2.000000000000001]
But, as you know, it is not the exact answer.
So, I wonder if there is something I can do to achieve a better performance and get [0.1,0.2,0.3,0.4..] as the result.
Thanks. _______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners