Scale Factor Fitting for Voltage

scale_factor_vs_voltage.py

%pylab inline
from hardware import *
import pyfog
import time
import pandas as pd
from scipy.optimize import curve_fit

scale_factors = pd.DataFrame(columns=['scale_factor'])

for vpp in linspace(1.6, 2.5, 5):
    awg.voltage = vpp
    time.sleep(2)
    scale_factors.loc[vpp] = fog.get_scale_factor(sensitivity=.1)
    
from scipy.optimize import curve_fit

def fit(V, A, Vpi):
    return -A*pi/(2*Vpi) * sin(V*pi/Vpi)

params, varmatrix = curve_fit(fit, scale_factors.index, 1/scale_factors['scale_factor'].values, p0=(max(1/scale_factors['scale_factor']), 2.25))
xs = linspace(1.5, 3.2, 40)
plot(1/scale_factors, 'o')
plot(xs, fit(xs, *params))

# Use this to get the scale factor for a given voltage
def sf(V):
    return 1/fit(V, *params)

print(params)