Title The General Interval Power Function
Author Oliver Heimlich
Date of Submission March 31, 2011
School Institute for Computer Science, University of Würzburg
Type of Thesis Diplomarbeit
Available Downloads BibTeX entry,
Full thesis (PDF, 613kB)


The present work develops and substantiates three differently extensive versions of a general power function: pow1, pow2 and pow3. Whilst the first only defines
powers with positive exponents, the second additionally defines powers of zero with positive exponent, as well as powers with negative base and integral exponent. The third version exceeds the former ones and additionally defines powers with negative base and rational exponent that can be written as a fraction with odd denominator.
Interval extensions as well as reverse interval operations are defined and presented for all three versions.
To act as a reference, a Matlab implementation is given, which uses the wellknown interval arithmetic library INTLAB.

Update: Since INTLAB is no longer available free of charge, the implemented functions have been migrated to Octave and are included in the free interval package. The new versions contain several bugfixes and improvements, e. g., they are faster (vectorized) and more accurate.


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