Hill Climbing In Artificial Intelligence:An Easy Guide(2021)

Introduction

Hill Climbing In Artificial Intelligence is used for optimizing the mathematical view of the given problems. Thus, in the sizable set of imposed inputs and heuristic functions, an algorithm tries to get the possible solution for the given problem in a reasonable allotted time. Hill climbing suits best when there is insufficient allotted time, and the problem may or may not have absolute results. Here, the definition states that hill-climbing solves the issues where there comes a need to minimize or maximize the real function by choosing the values from the input (that is also given).

A Hill Climbing algorithm example can be a traveling salesman’s problem where we may need to minimize or maximize the distance traveled by the salesman.

As the local search algorithm, it frequently maneuvers in the course of increasing value that helps to look for the best solutions to the problems. It terminates itself as it reaches the peak value having no neighbor adjacent to the higher value ranges. It is the technique that is used for resolving mathematical issues. It looks for the next immediate neighbor state; for example, there are two components of a node Hill Climbing algorithm with a value or a state.

Table of contents

1. Features of the Hill Climbing
2. Types of Hill Climbing
3. Various Areas in the State Space Diagram
4. Problems in different regions in Hill Climbing
5. Advantages and Disadvantages
6. Applications of Hill Climbing
7. Simulated Annealing
8. Case Study

1. Features of the Hill Climbing

1) Heuristic function

It is that function of Hill Climbing in AI that ranks all the potential alternatives in the search algorithm. It lets you get the possible solution to the given problem. That means the search algorithm may not only find the ideal solution to the given problem but will also let you have the best possible solution in the reasonable allotted time.

2) It is a generate-and-test algorithm variant.

The algorithm is followed as:

Step-1: Generates the best possible solutions

Step-2: Evaluate itself to see whether the best possible solution is the well-expected solution or not.

Step-3: If it suits the solution or the solution is found, then it quits; otherwise, it goes back to Step-1

Hill Climbing generates the procedure and decides the next possible move within the search area, and hence, it is called a generate-and-test algorithm that further adds to its best features.

If No

If Yes

3) Greedy Approach

In the state space, the Hill Climbing in artificial intelligence moves towards a  direction that best optimizes the output taken out in the direction of the solution. It optimizes the cost of function and moves till the end to get the solution.

If Yes

If No

2. Types of Hill Climbing

1) Steepest-Ascent Hill Climbing

It is a variation of simple Hill Climbing. It examines all the neighboring nodes in the existing state and selects the one that suits or is closest to the optimal state. It takes more time and searches for multiple neighbors.

• Continue the loop till no operator is left to apply to the algorithm.
• It examines the existing state, and if it is the goal state, it is a success.
• If the “new” state is more appropriate than the “existing” state, then set this state as the existing one.

2) Stochastic Hill Climbing

It doesn’t look over the neighboring nodes. It randomly selects one adjacent node. And, based on its pre-defined criteria, it decides whether to go for the existing state or go for any other alternative.

3) Simple Hill Climbing

It is one of the simplest ways to implement the Hill Climbing algorithm in artificial intelligence. Simple Hill Climbing evaluates the nearest nodes at the given time. It then selects the first output and optimizes the existing cost at the time. It checks the successor state, and if (in case) finds it more appropriate than the present state, it then goes in that state or else exits. The possible features of the simple hill algorithm are:

• Consumes less time
• Selects less optimal solution
• It does not guarantee a solution.

3. Various Areas in the State Space Diagram

• Local maximum: It is the state in which the existing state is more appropriate than the neighboring state, and here in this state, the value of the main function becomes higher than the neighbor’s value.

• Global maximum: It is the state where it possesses the highest value of the objective function.

• Plateau/flat local maximum: It is one of those states of the algorithm with the same value for all the neighboring nodes in the objective function. Therefore, it becomes challenging to select an appropriate direction of the solution.

• Ridge: It occurs when there are multiple peaks. All have the same value in this state, or you can call it a “global maxima.”

• Existing state: Here, in this state, the agent is currently present.

• Shoulder: It is the plateau region that has an uphill edge.

4. Problems in Different Regions in Hill Climbing

In case the Hill Climbing enters any of the following regions, it cannot find the best possible solution:

Local Maximum: To overcome the maximum local problem, you can utilize the backtracking technique. It requires maintaining the list of visited states. If, in case, the search reaches the undesirable state, backtracking to the previous configuration can explore the new path.

Plateau: to overcome plateaus, you can choose to make a big jump, i.e., select a state that is not near the existing state. Hence, landing in a non-plateau region becomes possible.

Ridge: To overcome a ridge, you can choose to utilize two or more rules before testing. In other words, it states that you can move in several directions at once.

5. Advantages and Disadvantages

Advantages of Hill Climbing In Artificial Intelligence

• Hill Climbing In Artificial Intelligence can be utilized nonstop, just like a domain. It is beneficial in routing the related problems—for example, portfolio management, chip designing, and job scheduling.
• Hill Climbing is a good option in optimizing the problems when you are limited to computational power.
• This one is more efficient in contrast to other search algorithms.
• Hill Climbing procedures are valuable in terms of vehicle routing, automatic programming, circuit designing, etc.
• It can tackle unadulterated advancement issues where the goal is to point out the best suitable state (following the procedure or the goal work).

Disadvantages of Hill Climbing In Artificial Intelligence

Hill Climbing Algorithm is one of the widely used algorithms for optimizing the given problems. It provides outstanding solutions to computationally challenging situations and has certain drawbacks also. The disadvantages related to it are:

• Local Minima
• Ridge
• Plateau

You can solve these drawbacks by using some advanced algorithms.

6. Applications of Hill Climbing

• The technique of Hill Climbing In Artificial Intelligence is used to solve many problems. It is used to tackle the issues where the existing state follows an accurate evaluation function—for example, traveling salesman problems, integrated circuit design, and network flow.
• The technique of Hill Climbing In Artificial Intelligence is also used in inductive learning methods. The method is used in robotics. It is utilized for coordinating with multiple robots in a team.

7. Simulated Annealing

To find the best optimal solution to the given problem, Hill Climbing always gets stuck in local maxima. This is because the downward moves in the Hill Climbing are not allowed. Simulated annealing is one of those techniques that let you have the downward steps to escape local maxima. The technique is used to yield both efficiency and completeness.

8. Case Study

Let’s create a code in the state that is ready to run:

Source link: https://www.gkbrk.com/wiki/hill_climbing/

Testing the Code

Source link: https://www.gkbrk.com/wiki/hill_climbing/

Conclusion

Hill Climbing in artificial intelligence is utilized to have decent values. It makes the excellent choice of easing the implementation in AI. You can choose to have alternative methods where simulated annealing or Hill Climbing may not prove to be good enough. Other methods like genetic algorithms, heuristic techniques (or the hyper-heuristic) can be used at some point in their algorithm.

Hill Climbing is an artificial intelligence algorithm that increases its value continually until it reaches the peak value. If you are planning to delve into the world of Artificial Intelligence and Machine Learning, boost your career growth with this Machine Learning And AI Course by Jigsaw Academy.

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