# What is Magpylib ?¶

• Python package for calculating 3D static magnetic fields of magnets (e.g. Cuboids, Cylinders, Spheres, …), line currents (e.g. straight or loops) and other sources (e.g. Dipoles).
• The fields are computed using analytical solutions which makes the computation very fast (fully vectorized)
• The field computation is coupled to a geometry interface (position, orientation, paths) which makes it convenient to determine relative motion between sources and observers. # When can you use Magpylib ?¶

The analytical solutions are exact when there is no material response. In permanent magnets, when (remanent) permeabilities are below the error is typically below 1% (long magnet shapes are better, large distance from magnet is better). For more details check out the physics section.

Magpylib is at its best when dealing with air-coils (no eddy currents) and high grade permanent magnet assemblies (Ferrite, NdFeB, SmCo or similar materials).

# Quickstart¶

Install Magpylib with pip or conda:

> pip install magpylib.

> conda install magpylib.

This Example code calculates the magnetic field of a cylindrical magnet.

import magpylib as mag3
s = mag3.magnet.Cylinder(magnetization=(0,0,350), dimension=(4,5))
observer_pos = (4,4,4)
print(s.getB(observer_pos))

# Output: [ 5.08641867  5.08641867 -0.60532983]


A cylinder shaped permanent magnet with diameter and height of 4 and 5 millimeter, respectively, is created in a global coordinate system with cylinder axis parallel to the z-axis and geometric magnet center in the origin. The magnetization is homogeneous and points in z-direction with an amplitude of 350 millitesla. The magnetic field is calculated in units of millitesla at the observer position (4,4,4) in units of millimeter.

Library Docstrings: