The ACCEL system - an introduction
-system is a light-weight, general purpose modelling environment for mathematical modelling. It combines some ideas from spreadsheets, Matlab, and traditional highschool mathematics. Its main features are the following:
- Named quantities and readible expressions. You write things like 'a=b+c*exp(-4*x)', and these expressions are numerically evaluated.
- Every '='-expression is in fact a functional definition: in 'a=b+c' you introduce a function that expresses 'a' in terms of the values of 'b' and 'c'.
ACCEL assumes that a mathematical model comes about iteratively. Each time a new (functional) definition is entered, it may contain quantities that have not yet been defined. ACCEL keeps track of these in a to-do list; once the to-do list is empty, the model is executable.
- Input quantities are set by means of direct manipulation using sliders, check boxes, input text fields or buttons.
- Output can be presented visually in the form of a dynamically scrolling graph for each output quantity. Graphs of various forms are supported.
ACCEL supports both statical and dynamical models: in evaluating expressions, quantities' earlier values can be queried, so a future state can be computed making use of present and past values of quantities.
ACCEL comes with intuitive fully automatic sensitivity analysis, showing the relative sensitivities of output quantities as functions of input quantities.
ACCEL has on-board genetic optimisation to deal with (statical) multiple-objective problems, using the SPEA algorithm by Sitzler et al.
ACCEL contains an extensive online help system explaining all built-in functions and other features.
ACCEL has a host of built-in linear algebra functions, courtesy of Peter Coxhead (http://www.cs.bham.ac.uk/~pxc/)
- Running directly in the browser, ACCEL requires no plugins or downloads, and it is completely free of charge.