[EPIC] Introducing Magnetic Flux Probes

[rocco8773]

1. Functionality for plasmapy.analysis
   • Create a bdot_probe.py
     • Create calc_bfield() function. Does not use units, strictly numpy arrays (probably 1D).
   • Create a sginal.py
     • Create remove_offset() function. Does not use units, strictly numpy arrays (probably 1D).
     • Create band_pass() function. Does not use units, strictly numpy arrays (probably 1D).
2. Functionality for plasmapy.diagnostics
   • Create bdot_porbe.py and a Bdot class.
     • Class will start enforcing units.
     • Probably start with just 1D data and then go into multiple signals and bdot axes.
     • Start by incorporating just the calc_bield() function, and then incorporate the other functions.

---

Proposed Framework

# in plasmapy/analysis/magnetics.py
import numpy as np


def calc_bfield(
    signal: np.ndarray,
    time: np.ndarray,
    *,
    area: float = None,
    nloops: int = None,
    gain: float = None,
) -> Tuple[np.ndarray, np.ndarray]:
    ...
    return bfield, new_time



# in plasmapy/diagnostics/magnetics.py
import astropy.units as u

from plasmapy.analysis.magnetics import calc_bfield
from plasmapy.utils.decorators import validate_quantities


class Bdot:
    _settings = {}
    _signal = None
    _time = None

    @validate_quantities
    def __init__(
        self,
        signal: u.volt,
        time: u.s,
        *,
        area: u.m**2,
        nloops,
        gain,
    ):
        self._signal = signal.value
        self._time = time.value
        self._settings = {
            "area": area.value,
            "nloops":, nloops,
            "gain": gain,
        }
    
    
    @validate_quantities
    def calc_bield(self) -> (u.T, u.s):
        
        bfield, new_time = calc_bfield(
            self._signal,
            self._time,
            **self._settings,
        )
        return bfield * u.T, new_time * u.s     

[aminaahmed1803]

I completed part one and opened a pull request (signal.py and bdot_probe.py #1652) for it

[StanczakDominik]

For the uninitiated, what does new_time represent?

[aminaahmed1803]

After integration of the bdot array, the resultant bfield array is one index shorter because of the integration. new_time is the array containing time values corresponding to bfield.

[svincena]

Definition : cumulative_trapezoid(y, x=None, dx=1.0, axis=-1, initial=None)

Typically, I like to specify the initial value of the trapezoidal integration scheme (usually zero), in which case the time arrays are the same and some overhead of passing in and out entire time arrays that are the same and as large (or off by one) as the data for many subsequent integrations is reduced.

[aminaahmed1803]

I created diagnostics/magnetics.py as formatted above. I haven't documented it yet. Just wanted to make sure it was correct first!