CustomParticle¶

class plasmapy.particles.CustomParticle(mass: Unit("kg") = None, charge: (Unit("C"), <class 'numbers.Real'>) = None)¶

Bases: plasmapy.particles.particle_class.AbstractParticle

A class to represent custom particles.

Example use cases for this class include representing an average ion in a multi-component plasma, molecules, or dust grains.

Parameters:	mass (Quantity, optional) – The mass of the custom particle in units of mass. charge (Quantity or Real) – The electric charge of the custom particle. If provided as a `Quantity`, then it must be in units of electric charge. If provided as a real number, then it is treated as the ratio of the charge to the elementary charge.
Raises:	`InvalidParticleError` – If the charge or mass provided is invalid so that the custom particle cannot be created.

See also

~plasmapy.particles.Particle ~plasmapy.particles.DimensionlessParticle

Notes

If the charge or mass is not specified, then the corresponding value will be set to numpy.nan in the appropriate units.

Examples

>>> from astropy import units as u
>>> from plasmapy.particles import CustomParticle
>>> custom_particle = CustomParticle(mass=1.5e-26 * u.kg, charge=-1)
>>> custom_particle.mass
<Quantity 1.5e-26 kg>
>>> custom_particle.charge
<Quantity -1.60217...e-19 C>

Attributes Summary

`charge`	Return the custom particle’s electric charge in coulombs.
`json_dict`	A `json` friendly dictionary representation of the particle.
`mass`	Return the custom particle’s mass.

Methods Summary

`json_dump`(fp, **kwargs)	Writes the particle’s `json_dict` to the `fp` file object using `json.dump`.
`json_dumps`(**kwargs)	Serialize the particle’s `json_dict` into a JSON formatted `str` using `json.dumps`.

Attributes Documentation

charge¶: Return the custom particle’s electric charge in coulombs.

json_dict¶

A json friendly dictionary representation of the particle. (see AbstractParticle.json_dict for more details)

Examples

>>> custom_particle = CustomParticle(mass=5.12 * u.kg, charge=6.2 * u.C)
>>> custom_particle.json_dict
{'plasmapy_particle': {'type': 'CustomParticle',
    'module': 'plasmapy.particles.particle_class',
    'date_created': '...',
    '__init__': {'args': (), 'kwargs': {'mass': '5.12 kg', 'charge': '6.2 C'}}}}
>>> custom_particle = CustomParticle(mass=1.5e-26 * u.kg)
>>> custom_particle.json_dict
{'plasmapy_particle': {'type': 'CustomParticle',
    'module': 'plasmapy.particles.particle_class',
    'date_created': '...',
    '__init__': {'args': (), 'kwargs': {'mass': '1.5e-26 kg', 'charge': 'nan C'}}}}

mass¶: Return the custom particle’s mass.

Methods Documentation

json_dump(fp, **kwargs)¶

Writes the particle’s json_dict to the fp file object using json.dump.

Parameters:	fp (file object) – Destination file object to write the JSON serialized `json_dict`. **kwargs – Any keyword accepted by `json.dump`.

json_dumps(**kwargs) → str¶

Serialize the particle’s json_dict into a JSON formatted str using json.dumps.

Parameters:	**kwargs – Any keyword accepted by `json.dumps`.
Returns:	JSON formatted `str`.
Return type:	str