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Pattern search (also known as direct search, derivative-free search, or black-box search) is a family of numerical optimization methods that does not require a gradient. As a result, it can be used on functions that are not continuous or differentiable. One such pattern search method is "convergence" (see below), which is based on the theory of ...
The algorithm works by iteratively assigning free variables, and when the algorithm encounters a bad assignment, then it backtracks to a previous iteration and chooses a different assignment of variables. It relies on a Branching Heuristic to pick the next free variable assignment; the branching algorithm effectively makes choosing the variable ...
Another example of heuristic making an algorithm faster occurs in certain search problems. Initially, the heuristic tries every possibility at each step, like the full-space search algorithm. But it can stop the search at any time if the current possibility is already worse than the best solution already found.
Variable neighborhood search (VNS), [1] proposed by Mladenović & Hansen in 1997, [2] is a metaheuristic method for solving a set of combinatorial optimization and global optimization problems. It explores distant neighborhoods of the current incumbent solution, and moves from there to a new one if and only if an improvement was made.
If h a (n) is an admissible heuristic function, in the weighted version of the A* search one uses h w (n) = ε h a (n), ε > 1 as the heuristic function, and perform the A* search as usual (which eventually happens faster than using h a since fewer nodes are expanded).
In computer science, local search is a heuristic method for solving computationally hard optimization problems. Local search can be used on problems that can be formulated as finding a solution that maximizes a criterion among a number of candidate solutions .
Given an initial assignment of values to all the variables of a constraint satisfaction problem (with one or more constraints not satisfied), select a variable from the set of variables with conflicts violating one or more of its constraints. Assign to this variable a value that minimizes the number of conflicts (usually breaking ties randomly).
It is a direct search method (based on function comparison) and is often applied to nonlinear optimization problems for which derivatives may not be known. However, the Nelder–Mead technique is a heuristic search method that can converge to non-stationary points [1] on problems that can be solved by alternative methods. [2]