Parallel implementation of the N-Body problem applied to the gravity force. The algorithm used is Barnes-Hut and the forces computations are parallelized using the MPI library.

To compile the program :

• Run the CMakeList with cmake .
• Run the makefile with make

To run the program the following arguments are necessary :

• Number of bodies
• Number of cluster of bodies
• Time step
• Final time
• Threshold for force computation
• Number of time step between each output

These arguments must be given in the order given above, example :

mpirun -np 2 ./NBodyMPI 40 1 0.01 50 3 1

The output is found in the file Output.dat in the following format for 3 time steps :

Body1_position_x Body1_position_y Body2_position_x Body2_position_y Body1_position_x Body1_position_y Body2_position_x Body2_position_y Body1_position_x Body1_position_y Body2_position_x Body2_position_y

The MATLAB file DrawBodies.m can be run to plot the output.