Institute for Reliable Computing
Head: Prof. Dr. Siegfried M. Rump

INTLAB - INTerval LABoratory

The Matlab/Octave toolbox for Reliable Computing Version 12

The Matlab/Octave toolbox for Reliable Computing

INTLAB is entirely written in Matlab. It works under Matlab and Octave. INTLAB ( see also the DEMOINTLAB) comprises of

and more. To cite INTLAB, please use RefBibTexINTLAB

There are a number of demo files for the different INTLAB toolboxes. You may view the demos directly, or copy the demos directory file into your working directory, change your directory by "cd demos" and call "demointlab".

INTLAB has several thousand users in more than 50 countries and more than 1200 citations in scientific publications.

INTLAB is used in many areas, from verification of chaos to population biology, from controller design to computer-assisted proofs, from PDEs to Petri Nets (cf. some selected Refences to INTLAB). Over the years many colleagues helped to improve INTLAB, my dearest thanks to them!

The main focus of INTLAB is to produce reliable results. Any result is proved to be true under any circumstances, in particular covering rounding errors and all error terms. The other main focus is to be fast.

The philosophy of INTLAB is that everything is written in Matlab code to assure best portability. Interval vector and matrix operations are very fast due to extensive use of BLAS routines. However, nonlinear computations and loops may slow down the system significantly due to interpretation overhead and extensive use of the operator concept.

Details and examples about timing can be found here. Moreover, some routines treat extremely ill-conditioned problems. Details and examples are here.

Further reading

Most routines in INTLAB are self-explaining and/or information can be obtained by the Matlab/Octave help command (cf. also readme.txt for more information).

For download and installation under Octave see here. Disclaimer: Few routines are not supported by Octave, in particular concerning graphics.

If you use INTLAB in publications, please include the reference

S.M. Rump: INTLAB - INTerval LABoratory. In Tibor Csendes, editor, Developments in Reliable Computing, pages 77-104. Kluwer Academic Publishers, Dordrecht, 1999.

INTLAB is thoroughly tested under Windows, Linux and MacOS operating system. It runs under the forthcoming Matlab version R2020b and is downward compatible at least to R2016b.

Unfortunately, changing the rounding mode does not work in Matlab version 2021a, but I was promised that this is planned to be fixed in the first update of version 2021b. Sorry for the inconvenience.

The parallel toolbox of Matlab applies only to a limited subset of Matlab utilities, therefore the parfor command and alike do not work with INTLAB. However, several incarnations of Matlab/INTLAB may run in parallel.


Copyright (c) 1998 - 2021 Siegfried M. Rump @ TUHH, Institute for Reliable Computing

All rights reserved.

===> INTLAB can be downloaded and used for private and for purely academic purposes, and for commercial purposes within a company. In any case proper reference has to be given acknowledging that the software package INTLAB has been developed by Siegfried M. Rump at Hamburg University of Technology, Germany.

===> The use of INTLAB in a commercial product which needs INTLAB or parts of INTLAB to work properly requires a special license. This is independent of whether the commercial product is used privately or for commercial purposes. To obtain such a license contact the author Siegfried M. Rump (

===> Neither the name of the university nor the name of the author may be used to endorse or promote products derived with or from this software without specific prior written permission.


DISCLAIMER: Extensive tests have been performed to ensure reliability of the algorithms. However, neither an error-free processor nor an error-free program can be guaranteed.

Prof. Dr. Siegfried M. Rump
Institute for Reliable Computing
Hamburg University of Technology
Am Schwarzenberg-Campus 3
21073 Hamburg