or-models 0.1.1

Some standard textbook Optimization Models and Algorithms.

or_models (Operations Research Models)

Mathematical Optimization Models and Algorithms

How to Install

You can use pip to install the code:

> pip install or_models

Models Included:

1. Set Covering Problem:

   Create an SCP object

   >>> costs = np.array([2,3,4,5])
   >>> matrix = np.array([[1,0,1,0],
                          [1,0,0,1],
                          [0,1,1,1]])
   >>> scp = SCP(costs,matrix)
   

   Solve with a MIP model created using Google OR-tools

   >>> scp.solve_with_GOR()
   

   Solve using Lagrange Relaxation method with some modification as discussed in

   Beasley, John E. "A lagrangian heuristic for set‐covering problems." Naval Research Logistics (NRL) 37.1 (1990): 151-164.

   >>> output = scp.LR_method(scp.row_least_cost,numIterations=1000)
   >>> print(output)
   (5, {0: 1, 1: 1})
   

Dependencies

• google or-tools
• numpy
• time