Improved Error Bounds for Inner Products in Floating-Point Arithmetic
Given two floating-point vectors $x,y$ of dimension $n$ and assuming rounding to nearest, we show that if no underflow or overflow occurs, any evaluation order for an inner product returns a floating-point number ${\widehat r}$ such that $|{\widehat r}- x^Ty| \leqslant nu|x|^T|y|$ with $u$ the unit...
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| Vydáno v: | SIAM journal on matrix analysis and applications Ročník 34; číslo 2; s. 338 - 344 |
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| Hlavní autoři: | , |
| Médium: | Journal Article |
| Jazyk: | angličtina |
| Vydáno: |
Philadelphia
Society for Industrial and Applied Mathematics
01.01.2013
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| Témata: | |
| ISSN: | 0895-4798, 1095-7162 |
| On-line přístup: | Získat plný text |
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| Shrnutí: | Given two floating-point vectors $x,y$ of dimension $n$ and assuming rounding to nearest, we show that if no underflow or overflow occurs, any evaluation order for an inner product returns a floating-point number ${\widehat r}$ such that $|{\widehat r}- x^Ty| \leqslant nu|x|^T|y|$ with $u$ the unit roundoff. This result, which holds for any radix and with no restriction on $n$, can be seen as a generalization of a similar bound given in [S. M. Rump, BIT, 52 (2012), pp. 201--220] for recursive summation in radix $2$, namely, $|{\widehat r}- x^Te| \leqslant (n-1)u|x|^Te$ with $e=[1,1,\ldots,1]^T$. As a direct consequence, the error bound for the floating-point approximation $\widehat{C}$ of classical matrix multiplication with inner dimension $n$ simplifies to $|\widehat{C}-AB|\leqslant nu|A||B|$. [PUBLICATION ABSTRACT] |
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| Bibliografie: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 14 ObjectType-Article-2 ObjectType-Feature-1 content type line 23 |
| ISSN: | 0895-4798 1095-7162 |
| DOI: | 10.1137/120894488 |