README.md

magpylib-force

This package provides force and torque computation for Magpylib objects. It is work in progress and will finally be integrated into the Magpylib package.

This work is supported by a NUMFOCUS grant: SDG 2024 round 1

Warning:

• relies on magpylib version>=5.0.1
• does not work with paths
• limited target types available

Documentation and Examples

The API documentation is integrated into the Magpylib docs.

Some examples are also part of the Magpylib webpage.

Example code:

import numpy as np
import magpylib as magpy
from magpylib_force import getFT

# Note: All inputs and outputs are in SI units.

# SOURCES: Magpylib source objects that generates the field
s1 = magpy.magnet.Sphere(diameter=1, polarization=(1, 2, 3))
s2 = magpy.magnet.Cuboid(dimension=(1, 1, 1), polarization=(1, 2, 3))

# TARGETS: targets that experience a force in the field of all sources
cube = magpy.magnet.Cuboid(
    dimension=(1, 1, 1),
    polarization=(0, 0, 1),
    position=(1, 2, 3),
)
cube.meshing = (5, 5, 5)  # regular rectangular mesh in Cuboid

line = magpy.current.Line(
    vertices=((2, 2, 2), (3, 3, 3), (3, 2, -3), (2, 2, 2)),
    current=1,
)
line.meshing = 15  # number of cells in each segment

# Note: use only closed current loops or be prepared to violate physics

sphere = magpy.magnet.Sphere(
    diameter=(6 / np.pi) ** (1 / 3),
    polarization=(0, 0, 1),
    position=(2, 2, 2),
)
sphere.meshing = 5  # grid finesse - the higher the finer

# COMPUTE FORCE AND TORQUE
FT = getFT([s1, s2], [cube, line, sphere], anchor=(0, 0, 0))

# Note: output shape is (3,2,3) from (targets, FT, xyz)
print(FT)

# Note: The magnet-numbers are large because the magnets are large :)