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On 08/22/2015 09:42 AM, R0b0t1 wrote: |
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> https://en.wikipedia.org/wiki/Round-off_error |
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> https://en.wikipedia.org/wiki/Machine_epsilon |
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> |
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> Either add a tolerance (a - b <= t) or compare them as strings as |
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> you've been doing. |
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> |
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You probably want |a - b| <= t there =) |
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But... that can cause problems too. If your numbers are small enough, |
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you can wind up with infinity or NaN (not a number) and then your |
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comparisons will go berserk. |
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|
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Floating point addition isn't even commutative: |
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|
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> 0.1 + 0.2 + 0.3 |
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0.6000000000000001 |
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> 0.1 + (0.2 + 0.3) |
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0.6 |
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|
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Better to avoid that quagmire entirely if you can. Use fixed point |
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arithmetic, arbitrary precision, or even rational numbers if you can get |
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away with it. |
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