Rules
We have adopted the following criteria in constructing our expert program:
PROBLEM DESCRIPTION
I. User input (by a friendly interface) :
- Define the problem variables.
- Define the right side of the ODE system (for example f from y'=f(y) ).
- Establish the integration interval.
- Establish the initial values.
II. Expert decisions:
- system linearity;
- sparsely and separable (for information storage schemes);
- problem classification in the idea to select a numerical method
(for example, a stiff-nonstiff classification).
METHOD DESCRIPTION
I. User input (by a friendly interface):
- Define the method variables.
- Define the equations at one step of the iterative process.
- Define the relationships between the old variables and the new variables in the reiteration case.
- Define the starting values in the case of a multistep method.
- Define a procedure as an implicit equation solver and a starting value for this procedure.
- Define a scheme for the error control.
II. Expert decisions:
- basic method classification (onestage/multistage, onestep/multistep, explicit/implicit, onederivative/multiderivative etc.);
- method order and method error;
- method stability;
- recommendation for a specific problem class.
APPROXIMATE SOLUTION COMPUTATION
I. User input (by a friendly interface ):
- error control;
- time control.
II. Expert decisions:
- abort computation in special cases;
- interpret the intermediate results;
- manipulate schemes with variable stepsize and variable formulae;
- reduce the computation time using concurrent computations.