Errors and Uncertainties in Computations Errors and Uncertainties ...
Errors and Uncertainties in Computations Errors and Uncertainties ...
Errors and Uncertainties in Computations Errors and Uncertainties ...
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
Theory: Types of <strong>Errors</strong> (4 plagues)<br />
1. Blunders: typos, wrong program, wrong data, …<br />
2. R<strong>and</strong>om errors: electronic fluctuations, cosmic rays, …<br />
– rare, but if 10 8 steps?<br />
– can't control<br />
– repeat calculation<br />
3. Approximation errors, algorithm, approx math:<br />
e −x =<br />
∞X<br />
n=0<br />
(−x) n<br />
n!<br />
'<br />
NX<br />
n=0<br />
(−x) n<br />
n!<br />
= e −x + E(x, N)<br />
(2)<br />
• decreases as N <strong>in</strong>creases<br />
• vanishes as N <br />
4. Round-Off <strong>Errors</strong> (cont)<br />
Introductory Computational Science 3<br />
© Rub<strong>in</strong> L<strong>and</strong>au, EPIC/OSU 2005
Change language