The recent GNU Octave [[Interval_package|interval package]] provides several arithmetic functions with accurate and guaranteed error bounds. Its development started in the end of 2014 and there is some fundamental functionality left to be implemented:
# Currently, everything is console/text only and the @infsup class needs functions for plotting intervals in graphs as lines, rectangles or boxes. For examples of how the result may look like, see images [http://www.maplesoft.com/applications/view.aspx?SID=4858&view=html] and [http://en.wikipedia.org/wiki/Interval_arithmetic].
# The functions <code>
fsolve</code>, <code> polyval</code>, and possibly <code>roots</code> shall be implemented for intervals (as m-files). 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, rpeval.cpp, and cpzero.cpp respectively). All required arithmetic operations already exist in the package.
'''Required skills''': m-file scripting, basic knowledge of computer arithmetics (especially floating-point computations)
'''Mentor''': Oliver Heimlich