Solving your First Problem
Using the Command Line Interface
The solver can be invoked from Windows PowerShell or Linux terminal using the following syntax:
octeract-engine [problem_file]
The solver supports direct input in ASL (.nl), MPS (.mps), and LP (.lp) formats. It also has built-in support for the Pyomo and AMPL modeling environments. Example input files are included in the installation folder under examples. Let’s begin by solving test problem ex2_1_1.nl.
Invoke the solver using the following command:
octeract-engine ex2_1_1.nl
You should see the following output:
-----------------------------------------------------------------------------------------------
Iteration GAP LLB BUB Pool Time Mem
-----------------------------------------------------------------------------------------------
11 5.000e-11 ( 0.00%) -1.700e+01 -1.700e+01 3 0.0s 91.0MB
Objective value at global solution: -1.700e+01
By default, the solver outputs the following information:
- Number of iterations (in this case, 11).
- Absolute and relative optimality gap (here \(5*10^{−11}\) and 0.00% respectively).
- Least Lower Bound (LLB). This is the smallest lower bound throughout the branch-and-bound tree.
- Best Upper Bound (BUB). This is the best local optimum that has been located so far.
- Pool. This is the number of nodes in the branching pool.
- Time. This is the real time (not CPU time) spent in branch-and-bound (in seconds).
- Memory. The amount of RAM that the solver is currently taking up.
By default, the solver will automatically write an .octsol solution file to the system’s
LOCAL_TEMP. This directory can be set explicitly (overridden) using the-s flag:
octeract-engine ex2_1_1.nl -d MY_SOLUTION_PATH
Detailed solution information can be accessed by inspecting the solution file (.octsol extension) in the selected location.
That’s it! Congratulations, you just solved your first problem using Octeract Engine!
Using Python
Check the Python API documentation for simple examples to get started.
Using C++
Check the C++ API documentation for simple examples to get started.
Choose your Framework
Octeract Engine supports six different frameworks in total. Select your preferred one below to start solving your model.
