## 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.

### 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.

Octeract Engine supports six different frameworks in total. Select your preferred one below to start solving your model.