no free-lunch theorem

no free-lunch theorem

1. No-free-lunch (NFL) theorem

2. There are so many algorithms for optimization, so what is the best one? Answer: NO Reasons that we cannot answer this question Complexity and diversity of real-world problems often mean that some problems are easier to solve, whereas others can be extremely difficult to solve A single method that can cope with all types of problems .

3. No-free-lunch (NFL) theorem There’s no one model that works for every problem Assumptions of a great model for one problem may not hold for another problem

4. No-free-lunch (NFL) theorem States that there is no universal algorithm for all problems Extremum - any point at which the value of a function is largest (a maximum) or smallest (a minimum). If any algorithm A outperforms another algorithm B in the search for an extremum of an objective function, then algorithm B will outperform A over other objective functions.

5. No-free-lunch (NFL) theorem NFL theorems apply to the scenario, either deterministic or stochastic, a set of continuous (or discrete or mixed) parameters θ maps the objective or cost function into a finite set

6. THANK YOU