iframe-proxy | Sunbelt Computer Software

History

executable file

94 lines (80 loc) · 2.95 KB

Raw

#!/usr/bin/env python3

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

# http://www.apache.org/licenses/LICENSE-2.0

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

"""Minimal example to call the GLOP solver."""

# [START program]

# [START import]

from ortools.init.python import init

from ortools.linear_solver import pywraplp

# [END import]

def main():

print("Google OR-Tools version:", init.OrToolsVersion.version_string())

# [START solver]

# Create the linear solver with the GLOP backend.

solver = pywraplp.Solver.CreateSolver("GLOP")

if not solver:

print("GLOP solver unavailable.")

return

# [END solver]

# [START variables]

# Create the variables x and y.

x_var = solver.NumVar(0, 1, "x")

y_var = solver.NumVar(0, 2, "y")

print("Number of variables =", solver.NumVariables())

# [END variables]

# [START constraints]

infinity = solver.infinity()

# Create a linear constraint, x + y <= 2.

constraint = solver.Constraint(-infinity, 2, "ct")

constraint.SetCoefficient(x_var, 1)

constraint.SetCoefficient(y_var, 1)

print("Number of constraints =", solver.NumConstraints())

# [END constraints]

# [START objective]

# Create the objective function, 3 * x + y.

objective = solver.Objective()

objective.SetCoefficient(x_var, 3)

objective.SetCoefficient(y_var, 1)

objective.SetMaximization()

# [END objective]

# [START solve]

print(f"Solving with {solver.SolverVersion()}")

result_status = solver.Solve()

# [END solve]

# [START print_solution]

print(f"Status: {result_status}")

if result_status != pywraplp.Solver.OPTIMAL:

print("The problem does not have an optimal solution!")

if result_status == pywraplp.Solver.FEASIBLE:

print("A potentially suboptimal solution was found")

else:

print("The solver could not solve the problem.")

return

print("Solution:")

print("Objective value =", objective.Value())

print("x =", x_var.solution_value())

print("y =", y_var.solution_value())

# [END print_solution]

# [START advanced]

print("Advanced usage:")

print(f"Problem solved in {solver.wall_time():d} milliseconds")

print(f"Problem solved in {solver.iterations():d} iterations")

# [END advanced]

if __name__ == "__main__":

init.CppBridge.init_logging("basic_example.py")

cpp_flags = init.CppFlags()

cpp_flags.stderrthreshold = True

cpp_flags.log_prefix = False

init.CppBridge.set_flags(cpp_flags)

main()

# [END program]

Sunbelt Computer Software

PL/B Language Development and Support

Navigation Menu

Uh oh!

Sunbelt Computer Software

PL/B Language Development and Support

Uh oh!

FilesExpand file tree

basic_example.py

Latest commit

History

basic_example.py

File metadata and controls