Mag probe module - issues with astropy.units

.gitignore

@@ -98,6 +98,7 @@ ENV/
 
 # Spyder project settings
 .spyderproject
+.spyproject
 
 # Rope project settings
 .ropeproject

hack/mag_probe_module.py

@@ -0,0 +1,73 @@
+# -*- coding: utf-8 -*-
+"""
+Created on Fri Jul 15 08:15:38 2022
+
+@author: xuans
+"""
+
+'''An initial attempt to implement a magnetic pickup probe module.'''
+
+import astropy.units as u
+
+import numpy as np
+
+from plasmapy.utils.decorators import validate_quantities
+
+@validate_quantities(
+    validations_on_return=u.T
+)
+def probe_to_field(raw: u.V, turns, area: u.m**2, t_step: u.s) -> u.T:
+    '''Taking, as input, raw voltage from magnetic probe 
+    (and number of coil turns) and convert it to magnetic field measurement 
+    at that location.
+
+    We assume [raw] is an np.array of voltages. Turns is the number of turns
+    in the pick-up coil. Area is the area of a single turn in the pick-up coil.
+    t_step is the time step between consecutive voltage measurements,
+    assumed to be uniform given a fixed sampling frequency.
+
+    The output voltage depends on the rate of change of the magnetic flux.
+
+    The induced voltage in a circuit is proportional to the rate of change
+    over time of the magnetic flux through that circuit.
+
+    emf is measured in volts. We are given volts.
+
+    emf = - N dPhi_N/ dt 
+
+    phi_B = surf_integral{B(t) dot dA}
+
+    To simplify, we assume we are computing the probe-aligned B field.
+    So phi_B_surf = B(t)_surf * A = B(t)_surf * turns * area 
+    '''
+
+    # we assume instantaneous measurement of 0 to raw.
+    #raw = - turns * area * B_probe / t_step
+
+    B_probe = []
+
+    # now expand to an array of voltages with fixed time step time traces
+    for i, v in enumerate(raw):
+        mag_field = ((raw[i] - raw[i-1]) * t_step) / (turns * area)
+        B_probe.append(mag_field)
+
+    #B_probe = np.array(B_probe)
+
+
+    # include manual casting to Tesla as workaround
+    return B_probe#.to(u.T)
+
+
+# provide synthetic signal - sine function TODO.
+measured_volts = np.linspace(0, 10, 2) * u.mV
+print(measured_volts)
+#for i in range(len(measured_volts)):
+#     measured_volts[i] = measured_volts[i] * u.V
+print(measured_volts)
+
+measured_field = probe_to_field(measured_volts, 10, 0.1*0.1 * u.m**2, 0.01 * u.s)
+
+print(measured_field)    
+
+
+