This code calculates the B-field of a cylindrical magnet at any point in 3D space given magnetic moment, radius, and height.
I use a bound-current approximation, discretized into rings. I discretize these rings into arcs, and solve for the B-field at any given point using Biot-Savart and the superposition principle. It's of course quite flexible, and can be extended for use as a current-ring, solenoid, or hemholtz coil field simulation.
i wrote it for IYPT so if u end up using it for some YPT around the world pls let me know and we can chat a bit!
uhh bfield and threaded_bfield are single worker and multi-worker (multithreaded) versions of the same thing. (removed now cause jit was just faster) It actually takes quite a bit of latency to spawn so many workers, so if u can use bfield and make ur calls threaded. bfield_threaded discretizes the current rings into chunks which is faster once u have approximately 80 or more discretizations
import bfield
# OR
import threaded_bfield as bfield
bfield.solution(np.array([0,0,2]),moment=0.8,mradius=0.02,mheight=0.01,accuracy=[80,80])# Python Packages
numpy
matplotlib
numba
srry for teh messy code, this is just some stuff i used for iypt that it hought id publish ya :P
also i wrote this in like 2 hours on the 高铁从from kunming到深圳 so like there may be issues no guarantees 😔
(NEW ALGORITHM)
(OLD ALGORITHM)
(Relative to a high-fidelity simulation)
## Parameters
# 100 VT-DISC, 100 CIR-DISC, Averaged 100 Runs
# 4c8t system, Tiger Lake
Numba JIT-Based Solution
First Call: 1188 ms # Needs JIT compilation
Discrete Call Time: 2706 us
Segment Call Time: 270 ns
Multi-threaded Solution
First Call: 89 ms
Discrete Call Time: 94074 us
Segment Call Time: 9407 ns
Single-threaded Solution
First call: 246 ms
Discrete Call Time: 260706 us
Segment Call Time: 26070 ns
# Note: Scaling is roughly linear with discretizations, with 10x10 disc. I get a 32us call time (roughy 30,657 calls/sec!).
Griffiths, D. J. (2024). Introduction to Electrodynamics (5 ed.). Cambridge University. doi:10.1017/9781009397735. ISBN 978-1-009-39773-5.