Constraint Satisfaction: Methodology
Constraints
Try to apply constraints with values of the same order of magnitude as the
objective function. This will prevent a constraint from being over-considered
by the optimization process.
About the use of precision and solution distance in Constraint
Satisfactions
The solution distance option used in constraint satisfaction results takes
its meaning if and only if at least 2 solutions are sought.
This option ensures that the distance (Maxi (xi-yi)) between the
two solutions is not less than the value specified by the option.
In the case of more than two solutions, the distance considered is the
distance between the current solution and all previously found solutions.
Example of "solution distance" impact on the results:
| Problem set up: |
Formula.1: fxy = x*x + y*y
CST.1:
fxy == 25;
x > -100; x < 100;
y > -100; y < 100 |
| First trial
for options: Results options: Number of solutions: 100, distance
between solutions: 0.02.
Options: Precision: 0.001
Solutions found: around 50000 (due to precision) among which 100
satisfy the distance specified. |
 |
| Second trial
for options: If the precision and the distance between solutions
are increased, the span of the solutions increase (due to a larger
distance between solutions) and the computation time decreases (due to
less precision).
Results options: Number of solutions: 100, distance between solutions:
0.15.
Options: Precision: 0.1
Solutions found: Around 1700 (due to precision) among which 100
satisfy the distance specified. |
 |