ERCIM News No.24 - January 1996 - VTT

**by Eero Hyvonen and Stefano De Pascale**

**In the real world data available for financial and technical analysis, decisionmaking, design and planning is often imprecise in many ways. Advanced mathematical and computional techniques are usually needed for exploiting such information. In many applications, the ineactness of numerical values can be represented conveniently by a range of possible values, i.e. by an interval. In order to support software development in such situations, a family of generic C++ libraries for extended interval arithemetic, global optimization and constraint satisfaction is being developed. The goal of the libraries is to make latest developments in interval analysis available mainstream C++ programmers.**

Library Purpose

- LIA InC++: Overloads C++ functions and operators for extended interval arithmetic
- GIA InC++: Evaluation of interval function ranges globally; global
- unconstrained optimization
- CIF InC++: Evaluation of interval function sets in spreadsheet-like
- computations
- ICE InC++ Interval constraint programming in C++

In order to promote the use of interval techniques among financial planners, engineers and other end-users, the Microsoft Excel spreadsheet programme has been extended for interval computations. The idea is that interval arithmetic can be used as the computational basis for the next generation of spreadsheet programmes dealing with real world imprecise data. Implemantations at VTT include extended interval arithemetic as an Excel Add-In function package and Interval Constaraint Excel for solving interval constarint satisfaction problems.

Additional information is available from the following World Wide Web and ftp sites: http://www.vtt.fi/tte/projects/interval, ftp://ftp.vtt.fi/pub/projects/interval

Eero Hyvonen - VTT

Tel: +358 0 4566043

E-mail: eero.hyvonen@vtt.fi

or

Stefano De Pascale - VTT

Tel: +358 0 4566058

E-mail: stefano.depascale@vtt.fi

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