How to use C++ with Octeract Engine
explanation practical insight starter guide
C++ on Windows
Before reaching this guide, you'll have:
- downloaded the Engine.
- installed the Engine.
- installed your authentication token.
This guide is specifically for compiling C++ program on Visual Studio.
Step 1: Create your Visual Studio Project
- Download and open Visual Studio
- Click on Create a new Project
- Select C++ as the language
- Click on Console App template
- Click on Next
- Select a name for the project and click on Create
Step 2: Build Project
- Click on Build and then Build<Name of your project>
- Verify that there is no error
- Remove the code in the current window
- Copy the following code:
#include "octeract.h" //Add Octeract's header file
using namespace octeract;
int main()
{
auto m = Model(); //Define an empty model
m.add_variable("x1", 0, 1);
m.add_variable("x2", 0, 1);
m.add_variable("x3", 0, 1);
m.add_variable("x4", 0, 1);
m.add_variable("x5", 0, 1); //Declare variables and variable bounds
//Set an objective function
m.set_objective("42*x1 - 0.5*(100*x1*x1 + 100*x2*x2 + 100*x3*x3 + 100*x4*x4 + 100*x5*x5) + 44*x2 + 45*x3 + 47*x4 + 47.5*x5");
//Add a constraint
m.add_constraint("20*x1 + 12*x2 + 11*x3 + 7*x4 + 4*x5 <= 40");
//Solve model to global optimality using 4 cores
m.global_solve(4);
return 0;
}
//End program
- Click on Project then
C:/Program Files (x86)/Octeract/include/ - Click on Project then
C:/Program Files (x86)/Octeract/bin - Click on Project then
- Click on Project then
- Finally click Build then Build<Your Project Name>
Step 3: Run the Example
Click on the green arrow found at the top of your Visual Studio screen, in the middle.
And that's it - you're done!
You've just solved an optimisation problem using C++.
C++ on Linux
Before reaching this guide, you'll have:
- downloaded the Engine.
- installed the Engine.
- installed your authentication token.
Step 1: Open your Terminal
Open your favorite terminal.
Step 2: Get a C++ Compiler Installed
For Ubuntu:
apt install clang
For Centos7:
yum install centos-release-scl-rh
yum install llvm-toolset-7.0-clang
alternatives --install /usr/bin/clang++ clang++\ /opt/rh/llvm-toolset-7/root/usr/bin/clang++ 100
For Centos8:
yum install epel-release
yum install gcc-toolset-10
alternatives --install /usr/bin/g++ g++\ /opt/rh/gcc-toolset-10/root/usr/bin/g++ 100
Watch out for step 3 you will need to change
clang++ forg++ Step 3: Write a Model in C++
We'll start by creating a model in C++. To do this, open a text editor IDE session. Copy and paste the snippet to create a model. Once you have the program in your session, save the model as my_example in C++.
#include "octeract.h" //Add Octeract's header file
using namespace octeract;
int main()
{
auto m = Model(); //Define an empty model
//Declare variables and variable bounds
m.add_variable("x1", 0, 1);
m.add_variable("x2", 0, 1);
m.add_variable("x3", 0, 1);
m.add_variable("x4", 0, 1);
m.add_variable("x5", 0, 1);
//Set an objective function
m.set_objective("42*x1 - 0.5*(100*x1*x1 + 100*x2*x2 + 100*x3*x3 + 100*x4*x4 + 100*x5*x5) + 44*x2 + 45*x3 + 47*x4 + 47.5*x5");
//Add a constraint
m.add_constraint("20*x1 + 12*x2 + 11*x3 + 7*x4 + 4*x5 <= 40");
//Solve model to global optimality using 4 cores
m.global_solve(4);
return 0;
} //End program
Step 4: Compile the Program
To compile your freshly written program please execute the following command:
clang++ < path-to-api-exmple.cpp > -locteract -o api-example
Step 5: Solve the Model
In your Shell Session, you can run this file. To do this, use the name of the file in the command. There is an example in the snippet. From there, the solution will be displayed on the screen. An example of what your final screen should look like can be seen below.
./api-example
