Table of Contents

    Example Code for using the DIDV class

    Import the needed packages to run the test script.

    In [1]:

    from qetpy import DIDV
import matplotlib.pyplot as plt
import numpy as np
import h5py

%matplotlib inline

    /galbascratch/samwatkins/anaconda3/lib/python3.6/site-packages/h5py/__init__.py:36: FutureWarning: Conversion of the second argument of issubdtype from `float` to `np.floating` is deprecated. In future, it will be treated as `np.float64 == np.dtype(float).type`.
  from ._conv import register_converters as _register_converters

    Set all of the necessary parameters and load the traces from an HDF5 file in the repository.

    In [2]:

    # Setting various parameters that are specific to the dataset
Rshunt = 5.0e-3
Rbias_SG = 20000.0
Rfb = 5000.0
loopgain = 2.4
ADCperVolt = 65536.0/2.0
fs = 625.0e3
sgFreq = 100.0
sgAmp = 0.009381 /Rbias_SG
drivergain = 4.0
Rp = 0.0060367199999999998
Rload = Rshunt+Rp
dRload = 0.0001
R0 = 0.075570107054005367
dR0 = 8.96383052e-04

convToAmps = Rfb * loopgain * drivergain * ADCperVolt

saveResults = False

# load the dataset
with h5py.File('example_traces.h5','r') as f:
    rawTraces = np.array(f["rawTraces"])

fileSaveName = "example_traces_data"

# set the priors information, for use the priors fitting
priors = np.zeros(7)
invpriorsCov = np.zeros((7,7))
priors[0] = Rload
priors[1] = R0
invpriorsCov[0,0] = 1.0/dRload**2
invpriorsCov[1,1] = 1.0/dR0**2
dt0=-18.8e-6

    Run the processing package on the data.

    In [3]:

    didvfit = DIDV(rawTraces, fs, sgFreq, sgAmp, Rshunt, tracegain=convToAmps) #note that there are many more attributes
didvfit.processtraces()
didvfit.doallfits()
# didvfit.dofit(2) # just do one fit
didvfit.plot_full_trace()
    ../../_images/demos_didv_test_didv_7_0.png

    Let’s look at the fit parameters for the 2-pole fit.

    In [4]:

    didvfit.fitparams2

    Out[4]:

    array([ 2.91338904e-01,  1.96261960e+00,  1.87363027e-03,  9.97908425e-07,
       -1.88710545e-05])

    In [5]:

    didvfit.irwinparams2

    Out[5]:

    array([ 1.00000000e-02,  3.00000000e-01, -6.22036528e-02,  7.71482552e-01,
        2.90729547e-07,  4.28157207e-04, -1.88710545e-05])

    In [6]:

    didvfit.get_irwinparams_dict(2)

    Out[6]:

    {'rload': 0.01,
 'r0': 0.3,
 'beta': -0.062203652825646105,
 'l': 0.771482552122021,
 'L': 2.907295469988362e-07,
 'tau0': 0.00042815720654307293,
 'dt': -1.887105448791047e-05,
 'tau_eff': 0.0002413064572931682}

    Let’s see what dIdV(0) is.

    In [7]:

    didvfit.didvfit2_freqdomain[0].real

    Out[7]:

    0.44366389157720754

    What are the fall times?

    In [8]:

    didvfit.falltimes2

    Out[8]:

    array([1.00151672e-06, 2.41306457e-04])

    Let’s play with the plotting functions available.

    Let’s first plot all of this fits on the full trace.

    In [9]:

    didvfit.plot_full_trace(poles="all",plotpriors=True)
    ../../_images/demos_didv_test_didv_17_0.png

    Now let’s plot a single trace and save the file to the current directory. If a different directory is wanted, then use the savepath variable.

    In [10]:

    didvfit.plot_single_period_of_trace(poles=[2,3], lgcsave=True, savename="test")

    Let’s plot a zoomed in trace of just the 2 pole fit. Note that by default, all fits are plotted.

    In [11]:

    didvfit.plot_zoomed_in_trace(poles=2)
    ../../_images/demos_didv_test_didv_21_0.png

    Let’s flip the trace and shift it by half a period of the signal generator in order to see if there are any nonlinearities. Spoilter alert: there aren’t!

    In [12]:

    didvfit.plot_didv_flipped()
    ../../_images/demos_didv_test_didv_23_0.png

    Now let’s look at the real and imaginary parts of the dIdV.

    In [13]:

    didvfit.plot_re_im_didv(poles=[2,3])
    ../../_images/demos_didv_test_didv_25_0.png
    ../../_images/demos_didv_test_didv_25_1.png 
    In [ ]: