WorkingPrecision
- To: mathgroup at smc.vnet.net
- Subject: [mg23824] WorkingPrecision
- From: bernd at bio.vu.nl (Bernd Brandt)
- Date: Sat, 10 Jun 2000 03:00:40 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Dear members,
Is someone able to explain why Accuracy and Precision decrease when i increase WorkingPrecision ?
The following illustrates my question:
In:
ni = NIntegrate[x Sqrt[x], {x, 0, 25}, AccuracyGoal -> 6, PrecisionGoal -> 6,
WorkingPrecision -> 16, Compiled -> False]
In: Accuracy[ni]
Precision[ni]
Out: 13
Out: 16
In: ni - 1250
OUt: -1.506340140622342*10^-6
Doing the same with WorkingPrecision->32 will yield:
Accuracy[ni] returns 3
Precision[ni] returns 7
And: ni-1250 now is less accurate: -0. 10^-4
I am puzzled at this. Any help or a reference is highly appreciated.
Does someone have a good reference on Accuracy, Precision, AccuracyGoal, PrecisionGoal and WorkingPrecision?
Thank you,
Bernd Brandt