Last active
November 28, 2023 08:15
-
-
Save pmocz/bd2257fcddb64aa52e555d67a5557a18 to your computer and use it in GitHub Desktop.
Create your own N-body simulation (with Python): acceleration
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| def getAcc( pos, mass, G, softening ): | |
| """ | |
| Calculate the acceleration on each particle due to Newton's Law | |
| pos is an N x 3 matrix of positions | |
| mass is an N x 1 vector of masses | |
| G is Newton's Gravitational constant | |
| softening is the softening length | |
| a is N x 3 matrix of accelerations | |
| """ | |
| N = pos.shape[0]; | |
| a = np.zeros((N,3)); | |
| for i in range(N): | |
| for j in range(N): | |
| dx = pos[j,0] - pos[i,0]; | |
| dy = pos[j,1] - pos[i,1]; | |
| dz = pos[j,2] - pos[i,2]; | |
| inv_r3 = (dx**2 + dy**2 + dz**2 + softening**2)**(-1.5); | |
| a[i,0] += G * (dx * inv_r3) * mass[j]; | |
| a[i,1] += G * (dy * inv_r3) * mass[j]; | |
| a[i,2] += G * (dz * inv_r3) * mass[j]; | |
| return a |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment