Timeline for How to increase precision: $MinPrecision does not help
Current License: CC BY-SA 3.0
17 events
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| May 8, 2013 at 11:40 | comment | added | J. M.'s missing motivation♦ | @Oleksandr, I know. ;) | |
| May 8, 2013 at 11:38 | comment | added | Oleksandr R. |
@J.M. WorkingPrecision -> $MachinePrecision often works in this situation because switching on significance arithmetic is enough for precision tracking and $MaxExtraPrecision to be able to take care of the rest.
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| May 7, 2013 at 4:03 | comment | added | Anixx | It seems your Lagrange form does not work faster though... | |
| May 7, 2013 at 4:02 | comment | added | J. M.'s missing motivation♦ | @Anixx, what for? You could try it out yourself; I won't. | |
| May 7, 2013 at 4:01 | comment | added | J. M.'s missing motivation♦ | @Szabolcs, true. That's the cancellation inherent in computing high-degree barycentric interpolants at play. I'm surprised just forcing arbitrary precision and a modest number of digits to work with made for something reasonable. | |
| May 7, 2013 at 3:58 | comment | added | Anixx | What about WorkingPrecision -> $MaxNumber? | |
| May 7, 2013 at 3:58 | comment | added | Szabolcs |
@J.M. WorkingPrecision -> MachinePrecision doesn't though.
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| May 7, 2013 at 3:56 | comment | added | J. M.'s missing motivation♦ |
@Szabolcs, actually, now that I tried it out, WorkingPrecision -> $MachinePrecision works, too. >:)
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| May 7, 2013 at 3:55 | comment | added | Szabolcs |
@Anixx If you use an explicit WorkingPrecision setting, Mathematica will use its arbitrary precision arithmetic. This doesn't mean that it will use "infinitely many" digits. It'll start with as many digits as you ask for in WorkingPrecision, and it'll try to keep track of how much error accumulates during the calculations. It might run out of precision. Try e.g. your original Ni3 with Ni3[1.1`20]. It'll give you "zero", with a pink background. You can apply Precision to it to verify that it has none.
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| May 7, 2013 at 3:53 | comment | added | Szabolcs | @J.M. Ah, I see now. | |
| May 7, 2013 at 3:52 | comment | added | Szabolcs | To be precise, it runs out of precision around 1.5 for a precision setting of 20, around -1.2 for 30, and looks fine for 40 (for default plot range). | |
| May 7, 2013 at 3:52 | comment | added | J. M.'s missing motivation♦ |
@Anixx, as I said, with WorkingPrecision.
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| May 7, 2013 at 3:51 | comment | added | J. M.'s missing motivation♦ | @Szabolcs, well, I simplified OP's function a bit; that helped. | |
| May 7, 2013 at 3:50 | comment | added | Szabolcs |
You get this plot with WorkingPrecision -> 20? I get junk with that ... I needed a much higher value.
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| May 7, 2013 at 3:50 | comment | added | Anixx | How to force it to use arbitrary precision? | |
| May 7, 2013 at 3:49 | vote | accept | Anixx | ||
| May 7, 2013 at 3:49 | history | answered | J. M.'s missing motivation♦ | CC BY-SA 3.0 |