The GNU Octave interval package for real-valued interval arithmetic.
right|Plotting the interval enclosure of a function]]
== Distribution ==
http://octave.sourceforge. net/interval/ index.html Latest version at Octave Forge]
** <code>pkg install -forge interval</code>
http://octave.sourceforge. net/interval/overview.html function reference]** [ http://octave.sourceforge. net/interval/package_doc/index.html package documentation] (user manual)* [https:// trac. macports.org/ browser/ trunk/ dports/math/octave-interval MacPorts] for Mac OS X* [ http://www.freshports.org/math/octave-forge-interval/ FreshPorts] for FreeBSD
== Development status ==
** All required functions from IEEE Std 1788-2015, IEEE standard for interval arithmetic, are implemented. The standard was approved on June 11, 2015. It will remain active for ten years.**
Planned: more solvers *** <code>fsolve</code>, *** and possibly <code>roots</code> *** Algorithms can be migrated from the C-XSC Toolbox (C++ code) from [ http:// www2. math. uni-wuppertal.de/ wrswt/ xsc/ cxsc_new.html] ( see nlinsys. cpp, and cpzero.cpp respectively).** Planned: Improvement of the user documentation *** Explain more interval arithmetic concepts with examples from the package ** Planned: Interval version of <code>interp1</code>
tests for all functions, many tests for basic functions** No known bugs. The package is quite new and still has a small user base, so there might be hidden bugs. Also some advanced functions need more testing.
** Runs in GNU Octave 3.8.2
and 4.0.0** Known to run under GNU/Linux, Microsoft Windows, Mac OS X and FreeBSD
== Compatibility ==
The interval package's main goal is to be compliant with IEEE Std 1788-2015, so it is compatible with other standard-conforming implementations (on the set of operations described by the standard document).
=== Octave Forge simp package ===
* Basic operations can be found in both packages, but the availability of special functions depends
In GNU Octave the interval package can also be run alongside INTLAB.|<syntaxhighlight lang="octave"> # INTLAB intervals A1 = infsup (2, 3); B1 = hull (-4, A1); C1 = midrad (0, 2); # Interval package intervals pkg load interval A2 = infsup (2, 3); B2 = hull (-4, A2); C2 = midrad (0, 2); pkg unload interval # Computation with INTLAB A1 + B1 * C1 # Computation without INTLAB A2 + B2 * C2
Similar software ==
For C++ there is an open source interval library [ https:// github. com/ nehmeier/ libieeep1788/ libieeep1788] by Marco Nehmeier ( member of IEEE P1788) . It aims to be standard compliant with IEEE Std 1788-2015 and is designed in a modular way, supporting several interval data types and different flavors of interval arithmetic [http://www.youtube.com/watch?v=GOa9aWAZO_Q]. The GNU Octave interval package shares several unit tests with libieeep1788.
For C++, Pascal and Fortran there is a free interval library [http:// www2. math. uni- wuppertal. de/~ xsc/ xsc-sprachen. html XSC] . It is not compliant with IEEE Std 1788- 2015. Some parts of the GNU Octave interval package have been derived from C- XSC.
For MATLAB there is a proprietary interval arithmetic toolbox [http://www.ti3.tu-harburg.de/rump/intlab/ INTLAB] by Siegfried Rump. It had been free of charge for academic use in the past, but no longer is. Its origin dates back to 1999, so it is well tested and comprises a lot of functionality, especially for vector / matrix operations. INTLAB is compatible with GNU Octave since Version 9 [http://www.ti3.tuhh.de/rump/intlab/Octave/octave.html].