LSpackage 1.0

An implementation of Local Search algorithms based on single solution design

Local Search - Metaheuristic

Project GIT address: https://github.com/anduralex/LSpackage.git

This lib implements some algorithms described on the book “Metaheuristics - From Design to Implementation”, from El-Ghazali Talbi.

I am testing the lib and it is available via pip install.

At this moment, the implementation includes:

• Search

  • Local Search algorithms - Hill Climbing

Installation

Just get it:

pip install LSpackage

You will need to have pip installed on your system. On linux install the python-pip package.

Examples

LSpackage allows you to define problems and look for the solution with different strategies. A sample are in the hello_word.py.

The problem will try to create the string “HELLO WORLD” using localSearchAlg algorithm:

from code.models import SearchProblem
from code.local import hillClimbing,localSearchAlg,firstExpander

WORD = 'HELLO WORLD'

 class HelloProblem(SearchProblem):
   def actions(self, state):
       if len(state) < len(WORD):
           return list(' ABCDEFGHIJKLMNOPQRSTUVWXYZ')
       else:
           return []

   def result(self, state, action):
       return state+action

   def value(self, state):
       # how many correct letters there are?
       count=sum(1 if state[i] == WORD[i] else 0
                  for i in range(min(len(WORD), len(state))))
       return count

result = localSearchAlg(HelloProblem(initial_state=''),firstExpander)
print(result.state)

More detailed documentation

You can read the book “Metaheuristics - From Design to Implementation”, from El-Ghazali Talbi. Or for offline access, you can clone the project code repository and work with it.

Authors

• Andurnache Alexandru