qetpy.core package¶

qetpy.core._didv module¶

qetpy.core._didv.didvinitfromdata(tmean, didvmean, didvstd, offset, offset_err, fs, sgfreq, sgamp, rshunt, r0=0.3, r0_err=0.001, rload=0.01, rload_err=0.001, priors=None, invpriorscov=None, add180phase=False, dt0=1e-05)¶

Function to initialize and process a dIdV dataset without having all of the traces, but just the parameters that are required for fitting. After running, this returns a DIDV class object that is ready for fitting.

Parameters:

tmean : ndarray: The average trace in time domain, units of Amps
didvstd : ndarray: The complex standard deviation of the didv in frequency space for each frequency
didvmean : ndarray: The average trace converted to didv
offset : float: The offset (i.e. baseline value) of the didv trace, in Amps
offset_err : float: The error in the offset of the didv trace, in Amps
fs : float: Sample rate of the data taken, in Hz
sgfreq : float: Frequency of the signal generator, in Hz
sgamp : float: Amplitude of the signal generator, in Amps (equivalent to jitter in the QET bias)
rshunt : float: Shunt resistance in the circuit, Ohms
r0 : float, optional: Resistance of the TES in Ohms
r0_err : float, optional: Error in the resistance of the TES (Ohms)
rload : float, optional: Load resistance of the circuit (rload = rshunt + rparasitic), Ohms
rload_err : float, optional: Error in the load resistance, Ohms
priors : ndarray, optional: Prior known values of Irwin’s TES parameters for the trace. Should be in the order of (rload,r0,beta,l,L,tau0,dt)
invpriorscov : ndarray, optional: Inverse of the covariance matrix of the prior known values of Irwin’s TES parameters for the trace (any values that are set to zero mean that we have no knowledge of that parameter)
add180phase : boolean, optional: If the signal generator is out of phase (i.e. if it looks like –__ instead of __–), then this should be set to True. Adds half a period of the signal generator to the dt0 attribute
dt0 : float, optional: The value of the starting guess for the time offset of the didv when fitting. The best way to use this value if it isn’t converging well is to run the fit multiple times, setting dt0 equal to the fit’s next value, and seeing where the dt0 value converges. The fit can have a difficult time finding the value on the first run if it the initial value is far from the actual value, so a solution is to do this iteratively.

Returns:

didvobj : Object: A DIDV class object that can be used to fit the dIdV and return the fit parameters.

class qetpy.core._didv.DIDV(rawtraces, fs, sgfreq, sgamp, rshunt, tracegain=1.0, r0=0.3, r0_err=0.001, rload=0.01, rload_err=0.001, dutycycle=0.5, add180phase=False, priors=None, invpriorscov=None, dt0=1e-05)¶

Bases: object

Class for fitting a didv curve for different types of models of the didv. Also gives various other useful values pertaining to the didv. This class supports doing 1, 2, and 3 pole fits, as well as a 2 pole priors fit. This is supported in a way that does one dataset at a time.

Attributes:

rawtraces : ndarray: The array of rawtraces to use when fitting the didv. Should be of shape (number of traces, length of trace in bins). This can be any units, as long as tracegain will convert this to Amps.
fs : float: Sample rate of the data taken, in Hz
sgfreq : float: Frequency of the signal generator, in Hz
sgamp : float: Amplitude of the signal generator, in Amps (equivalent to jitter in the QET bias)
r0 : float: Resistance of the TES in Ohms
r0_err : float: Error in the resistance of the TES (Ohms)
rload : float: Load resistance of the circuit (rload = rshunt + rparasitic), Ohms
rload_err : float: Error in the load resistance, Ohms
rshunt : float: Shunt resistance in the circuit, Ohms
tracegain : float: The factor that the rawtraces should be divided by to convert the units to Amps. If rawtraces already has units of Amps, then this should be set to 1.0
dutycycle : float: The duty cycle of the signal generator, should be a float between 0 and 1. Set to 0.5 by default
add180phase : boolean: If the signal generator is out of phase (i.e. if it looks like –__ instead of __–), then this should be set to True. Adds half a period of the signal generator to the dt0 attribute
priors : ndarray: Prior known values of Irwin’s TES parameters for the trace. Should be in the order of (rload,r0,beta,l,L,tau0,dt)
invpriorscov : ndarray: Inverse of the covariance matrix of the prior known values of Irwin’s TES parameters for the trace (any values that are set to zero mean that we have no knowledge of that parameter)
dt0 : float: The value of the starting guess for the time offset of the didv when fitting. The best way to use this value if it isn’t converging well is to run the fit multiple times, setting dt0 equal to the fit’s next value, and seeing where the dt0 value converges. The fit can have a difficult time finding the value on the first run if it the initial value is far from the actual value, so a solution is to do this iteratively.
freq : ndarray: The frequencies of the didv fit
time : ndarray: The times the didv trace
ntraces : float: The number of traces in the data
traces : ndarray: The traces being used in units of Amps and also truncated so as to include only an integer number of signal generator periods
flatinds : ndarray: The indices where the traces are flat
tmean : ndarray: The average trace in time domain, units of Amps
zeroinds : ndarray: The indices of the didv fit in frequency space where the values should be zero
didvstd : ndarray: The complex standard deviation of the didv in frequency space for each frequency
didvmean : ndarray: The average trace converted to didv
offset : float: The offset (i.e. baseline value) of the didv trace, in Amps
offset_err : float: The error in the offset of the didv trace, in Amps
fitparams1 : ndarray: The fit parameters of the 1-pole fit, in order of (A, tau2, dt)
fitcov1 : ndarray: The corresponding covariance for the 1-pole fit parameters
fitcost1 : float: The cost of the 1-pole fit
irwinparams1 : ndarray: The Irwin parameters of the 1-pole fit, in order of (rtot, L , r0, rload, dt)
irwincov1 : ndarray: The corresponding covariance for the Irwin parameters for the 1-pole fit
falltimes1 : ndarray: The fall times of the 1-pole fit, same as tau2, in s
didvfit1_timedomain : ndarray: The 1-pole fit in time domain
didvfit1_freqdomain : ndarray: The 1-pole fit in frequency domain
fitparams2 : ndarray: The fit parameters of the 2-pole fit, in order of (A, B, tau1, tau2, dt)
fitcov2 : ndarray: The corresponding covariance for the 2-pole fit parameters
fitcost2 : float: The cost of the 2-pole fit
irwinparams2 : ndarray: The Irwin parameters of the 2-pole fit, in order of (rload, r0, beta, l, L, tau0, dt)
irwincov2 : ndarray: The corresponding covariance for the Irwin parameters for the 2-pole fit
falltimes2 : ndarray: The fall times of the 2-pole fit, tau_plus and tau_minus, in s
didvfit2_timedomain : ndarray: The 2-pole fit in time domain
didvfit2_freqdomain : ndarray: The 2-pole fit in frequency domain
fitparams3 : ndarray: The fit parameters of the 3-pole fit, in order of (A, B, C, tau1, tau2, tau3, dt)
fitcov3 : ndarray: The corresponding covariance for the 3-pole fit parameters
fitcost3 : float: The cost of the 3-pole fit
irwinparams3 : NoneType: The Irwin parameters of the 3-pole fit, this returns None now, as there is no model that we convert to
irwincov3 : NoneType: The corresponding covariance for the Irwin parameters for the 3-pole fit, also returns None
falltimes3 : ndarray: The fall times of the 3-pole fit in s
didvfit3_timedomain : ndarray: The 3-pole fit in time domain
didvfit3_freqdomain : ndarray: The 3-pole fit in frequency domain
fitparams2priors : ndarray: The fit parameters of the 2-pole priors fit, in order of (A, B, tau1, tau2, dt), converted from the Irwin parameters
fitcov2priors : ndarray: The corresponding covariance for the 2-pole priors fit parameters
fitcost2priors : float: The cost of the 2-pole priors fit
irwinparams2priors : ndarray: The Irwin parameters of the 2-pole priors fit, in order of (rload, r0, beta, l, L, tau0, dt)
irwincov2priors : ndarray: The corresponding covariance for the Irwin parameters for the 2-pole priors fit
falltimes2priors : ndarray: The fall times of the 2-pole priors fit, tau_plus and tau_minus, in s
didvfit2priors_timedomain : ndarray: The 2-pole priors fit in time domain
didvfit2priors_freqdomain : ndarray: The 2-pole priors fit in frequency domain

Methods

`doallfits`()	This module does all of the fits consecutively.
`dofit`(poles)	This method does the fit that is specified by the variable poles.
`dopriorsfit`()	This module runs the priorsfit, assuming that the priors and invpriorscov attributes have been set to the proper values.
`get_irwinparams_dict`(poles[, lgcpriors])	Returns a dictionary with the irwin fit parameters for a given number of poles
`plot_didv_flipped`([poles, plotpriors, …])	Module to plot the flipped trace in time domain.
`plot_full_trace`([poles, plotpriors, …])	Module to plot the entire trace in time domain
`plot_re_im_didv`([poles, plotpriors, …])	Module to plot the real and imaginary parts of the didv in frequency space.
`plot_single_period_of_trace`([poles, …])	Module to plot a single period of the trace in time domain
`plot_zoomed_in_trace`([poles, zoomfactor, …])	Module to plot a zoomed in portion of the trace in time domain.
`processtraces`()	This method processes the traces loaded to the DIDV class object.

doallfits()¶: This module does all of the fits consecutively. The priors fit is not done if the attributes priors and invpriorscov have not yet been set.

dofit(poles)¶

This method does the fit that is specified by the variable poles. If the processtraces module has not been run yet, then this module will run that first. This module does not do the priors fit.

Parameters:	poles : int The fit that should be run. Should be 1, 2, or 3.

dopriorsfit()¶: This module runs the priorsfit, assuming that the priors and invpriorscov attributes have been set to the proper values.

get_irwinparams_dict(poles, lgcpriors=False)¶

Returns a dictionary with the irwin fit parameters for a given number of poles

Parameters:	poles: int The number of poles used for the fit lgcpriors: bool, optional If true, the values from the priors fit are returned
Returns:	return_dict: dictionary The irwim parameters stored in a dictionary

plot_didv_flipped(poles='all', plotpriors=True, lgcsave=False, savepath='', savename='')¶

Module to plot the flipped trace in time domain. This function should be used to test if there are nonlinearities in the didv

Parameters:

poles : int, string, array_like, optional: The pole fits that we want to plot. If set to “all”, then plots all of the fits. Can also be set to just one of the fits. Can be set as an array of different fits, e.g. [1, 2]
plotpriors : boolean, optional: Boolean value on whether or not the priors fit should be plotted.
lgcsave : boolean, optional: Boolean value on whether or not the figure should be saved
savepath : string, optional: Where the figure should be saved. Saved in the current directory by default.
savename : string, optional: A string to append to the end of the file name if saving. Empty string by default.

plot_full_trace(poles='all', plotpriors=True, lgcsave=False, savepath='', savename='')¶

Module to plot the entire trace in time domain

Parameters:

poles : int, string, array_like, optional: The pole fits that we want to plot. If set to “all”, then plots all of the fits. Can also be set to just one of the fits. Can be set as an array of different fits, e.g. [1, 2]
plotpriors : boolean, optional: Boolean value on whether or not the priors fit should be plotted.
lgcsave : boolean, optional: Boolean value on whether or not the figure should be saved
savepath : string, optional: Where the figure should be saved. Saved in the current directory by default.
savename : string, optional: A string to append to the end of the file name if saving. Empty string by default.

plot_re_im_didv(poles='all', plotpriors=True, lgcsave=False, savepath='', savename='')¶

Module to plot the real and imaginary parts of the didv in frequency space. Currently creates two different plots.

Parameters:

poles : int, string, array_like, optional: The pole fits that we want to plot. If set to “all”, then plots all of the fits. Can also be set to just one of the fits. Can be set as an array of different fits, e.g. [1, 2]
plotpriors : boolean, optional: Boolean value on whether or not the priors fit should be plotted.
lgcsave : boolean, optional: Boolean value on whether or not the figure should be saved
savepath : string, optional: Where the figure should be saved. Saved in the current directory by default.
savename : string, optional: A string to append to the end of the file name if saving. Empty string by default.

plot_single_period_of_trace(poles='all', plotpriors=True, lgcsave=False, savepath='', savename='')¶

Module to plot a single period of the trace in time domain

Parameters:

poles : int, string, array_like, optional: The pole fits that we want to plot. If set to “all”, then plots all of the fits. Can also be set to just one of the fits. Can be set as an array of different fits, e.g. [1, 2]
plotpriors : boolean, optional: Boolean value on whether or not the priors fit should be plotted.
lgcsave : boolean, optional: Boolean value on whether or not the figure should be saved
savepath : string, optional: Where the figure should be saved. Saved in the current directory by default.
savename : string, optional: A string to append to the end of the file name if saving. Empty string by default.

plot_zoomed_in_trace(poles='all', zoomfactor=0.1, plotpriors=True, lgcsave=False, savepath='', savename='')¶

Module to plot a zoomed in portion of the trace in time domain. This plot zooms in on the overshoot of the didv.

Parameters:

poles : int, string, array_like, optional: The pole fits that we want to plot. If set to “all”, then plots all of the fits. Can also be set to just one of the fits. Can be set as an array of different fits, e.g. [1, 2]
zoomfactor : float, optional, optional: Number between zero and 1 to show different amounts of the zoomed in trace.
plotpriors : boolean, optional: Boolean value on whether or not the priors fit should be plotted.
lgcsave : boolean, optional: Boolean value on whether or not the figure should be saved
savepath : string, optional: Where the figure should be saved. Saved in the current directory by default.
savename : string, optional: A string to append to the end of the file name if saving. Empty string by default.

processtraces()¶: This method processes the traces loaded to the DIDV class object. This sets up the object for fitting.

qetpy.core._fitting module¶

qetpy.core._fitting.ofamp(signal, template, psd, fs, withdelay=True, coupling='AC', lgcsigma=False, nconstrain=None, lgcoutsidewindow=False, integralnorm=False)¶

Function for calculating the optimum amplitude of a pulse in data. Supports optimum filtering with and without time delay.

Parameters:

signal : ndarray: The signal that we want to apply the optimum filter to (units should be Amps). Can be an array of traces.
template : ndarray: The pulse template to be used for the optimum filter (should be normalized beforehand).
psd : ndarray: The two-sided psd that will be used to describe the noise in the signal (in Amps^2/Hz)
fs : float: The sample rate of the data being taken (in Hz).
withdelay : bool, optional: Determines whether or not the optimum amplitude should be calculate with (True) or without (False) using a time delay. With the time delay, the pulse is assumed to be at any time in the trace. Without the time delay, the pulse is assumed to be directly in the middle of the trace. Default is True.
coupling : str, optional: String that determines if the zero frequency bin of the psd should be ignored (i.e. set to infinity) when calculating the optimum amplitude. If set to ‘AC’, then ths zero frequency bin is ignored. If set to anything else, then the zero frequency bin is kept. Default is ‘AC’.
lgcsigma : Boolean, optional: If True, the estimated optimal filter energy resolution will be calculated and returned.
nconstrain : int, NoneType, optional: The length of the window (in bins) to constrain the possible t0 values to, centered on the unshifted trigger. If left as None, then t0 is uncontrained. If nconstrain is larger than nbins, then the function sets nconstrain to nbins, as this is the maximum number of values that t0 can vary over.
lgcoutsidewindow : bool, optional: Boolean flag that is used to specify whether ofamp should look inside nconstrain or outside it. If False, ofamp will minimize the chi^2 in the bins specified by nconstrain, which is the default behavior. If True, then ofamp will minimize the chi^2 in the bins that do not contain the constrained window.
integralnorm : bool, optional: If set to True, then ofamp will normalize the template to an integral of 1, and ofamp will instead return the optimal integral in units of Coulombs. If lgcsigma is set to True, then it will be returned in units of Coulombs as well. If set to False, then the usual optimal filter amplitude will be returned (in units of Amps).

Returns:

amp : float: The optimum amplitude calculated for the trace (in Amps).
t0 : float: The time shift calculated for the pulse (in s). Set to zero if withdelay is False.
chi2 : float: The chi^2 value calculated from the optimum filter.
sigma : float, optional: The optimal filter energy resolution (in Amps)

qetpy.core._fitting.ofamp_pileup(signal, template, psd, fs, a1=None, t1=None, coupling='AC', nconstrain1=None, nconstrain2=None, lgcoutsidewindow=True)¶

Function for calculating the optimum amplitude of a pileup pulse in data. Supports inputted the values of a previously known pulse for increased computational speed, but can be used on its own.

Parameters:

signal : ndarray: The signal that we want to apply the optimum filter to (units should be Amps).
template : ndarray: The pulse template to be used for the optimum filter (should be normalized beforehand).
psd : ndarray: The two-sided psd that will be used to describe the noise in the signal (in Amps^2/Hz)
fs : float: The sample rate of the data being taken (in Hz).
a1 : float, optional: The OF amplitude (in Amps) to use for the “main” pulse, e.g. the triggered pulse. This should be calculated beforehand using ofamp. This is only used if t1 is also inputted.
t1 : float, optional: The corresponding time offset (in seconds) to use for the “main” pulse, e.g. the triggered pulse. As with a1, this should be calculated beforehand using ofamp. This is only used if a1 is also inputted.
coupling : str, optional: String that determines if the zero frequency bin of the psd should be ignored (i.e. set to infinity) when calculating the optimum amplitude. If set to ‘AC’, then ths zero frequency bin is ignored. If set to anything else, then the zero frequency bin is kept. Default is ‘AC’.
nconstrain1 : int, NoneType, optional: If t1 is left as None, this is the length of the window (in bins) to constrain the possible t1 values to for the first pulse, centered on the unshifted trigger. If left as None, then t1 is uncontrained. If nconstrain1 is larger than nbins, then the function sets nconstrain1 to nbins, as this is the maximum number of values that t1 can vary over. This is only used if a1 or t1 is not given.
nconstrain2 : int, NoneType, optional: This is the length of the window (in bins) out of which to constrain the possible t2 values to for the pileup pulse, centered on the unshifted trigger. If left as None, then t2 is uncontrained. The value of nconstrain2 should be less than nbins.
lgcoutsidewindow : bool, optional: Boolean flag that is used to specify whether ofamp_pileup should look for the pileup pulse inside the bins specified by nconstrain2 or outside them. If True, ofamp will minimize the chi^2 in the bins ouside the range specified by nconstrain2, which is the default behavior. If False, then ofamp will minimize the chi^2 in the bins inside the constrained window specified by nconstrain2.

Returns:

a1 : float: The optimum amplitude (in Amps) calculated for the first pulse that was found, which is generally the triggered pulse.
t1 : float: The time shift calculated for the first pulse that was found (in s)
a2 : float: The optimum amplitude calculated for the pileup pulse (in Amps).
t2 : float: The time shift calculated for the pileup pulse (in s)
chi2 : float: The chi^2 value calculated for the pileup optimum filter.

qetpy.core._fitting.ofamp_pileup_stationary(signal, template, psd, fs, coupling='AC', nconstrain=None, lgcoutsidewindow=False)¶

Function for calculating the optimum amplitude of a pileup pulse in data, with the assumption that the triggered pulse is centered in the trace.

Parameters:

signal : ndarray: The signal that we want to apply the optimum filter to (units should be Amps).
template : ndarray: The pulse template to be used for the optimum filter (should be normalized beforehand).
psd : ndarray: The two-sided psd that will be used to describe the noise in the signal (in Amps^2/Hz)
fs : float: The sample rate of the data being taken (in Hz).
coupling : str, optional: String that determines if the zero frequency bin of the psd should be ignored (i.e. set to infinity) when calculating the optimum amplitude. If set to ‘AC’, then ths zero frequency bin is ignored. If set to anything else, then the zero frequency bin is kept. Default is ‘AC’.
nconstrain : int, NoneType, optional: This is the length of the window (in bins) out of which to constrain the possible t2 values to for the pileup pulse, centered on the unshifted trigger. If left as None, then t2 is uncontrained. The value of nconstrain should be less than nbins.
lgcoutsidewindow : bool, optional: Boolean flag that is used to specify whether the function should look for the pileup pulse inside the bins specified by nconstrain or outside them. If True, ofamp will minimize the chi^2 in the bins ouside the range specified by nconstrain, which is the default behavior. If False, then ofamp will minimize the chi^2 in the bins inside the constrained window specified by nconstrain.

Returns:

a1 : float: The optimum amplitude (in Amps) calculated for the first pulse that was found, which is the triggered pulse.
a2 : float: The optimum amplitude calculated for the pileup pulse (in Amps).
t2 : float: The time shift calculated for the pileup pulse (in s)
chi2 : float: The reduced chi^2 value of the fit.

qetpy.core._fitting.chi2lowfreq(signal, template, amp, t0, psd, fs, fcutoff=10000)¶

Function for calculating the low frequency chi^2 of the optimum filter, given some cut off frequency. This function does not calculate the optimum amplitude - it requires that ofamp has been run, and the fit has been loaded to this function.

Parameters:

signal : ndarray: The signal that we want to calculate the low frequency chi^2 of (units should be Amps).
template : ndarray: The pulse template to be used for the low frequency chi^2 calculation (should be normalized beforehand).
amp : float: The optimum amplitude calculated for the trace (in Amps).
t0 : float: The time shift calculated for the pulse (in s).
psd : ndarray: The two-sided psd that will be used to describe the noise in the signal (in Amps^2/Hz).
fs : float: The sample rate of the data being taken (in Hz).
fcutoff : float, optional: The frequency (in Hz) that we should cut off the chi^2 when calculating the low frequency chi^2.

Returns:

chi2low : float: The low frequency chi^2 value (cut off at fcutoff) for the inputted values.

qetpy.core._fitting.chi2_nopulse(signal, psd, fs, coupling='AC')¶

Function for calculating the chi^2 of a trace with the assumption that there is no pulse.

Parameters:

signal : ndarray: The signal that we want to calculate the no pulse chi^2 of (units should be Amps).
psd : ndarray: The two-sided psd that will be used to describe the noise in the signal (in Amps^2/Hz).
fs : float: The sample rate of the data being taken (in Hz).
coupling : str, optional: String that determines if the zero frequency bin of the psd should be ignored (i.e. set to infinity) when calculating the no pulse chi^2 . If set to ‘AC’, then the zero frequency bin is ignored. If set to anything else, then the zero frequency bin is kept. Default is ‘AC’.

Returns:

chi2_0 : float: The chi^2 value for there being no pulse.

class qetpy.core._fitting.OFnonlin(psd, fs, template=None)¶

Bases: object

This class provides the user with a non-linear optimum filter to estimate the amplitude, rise time (optional), fall time, and time offset of a pulse.

Methods

`calcchi2`(model)	Function to calculate the reduced chi square
`fit_falltimes`(pulse[, lgcdouble, errscale, …])	Function to do the fit
`onepole`(A, tau_f, t0)	Functional form of pulse in time domain with the amplitude, fall time, and time offset allowed to float, and the rise time held constant
`residuals`(params)	Function ot calculate the weighted residuals to be minimized
`twopole`(A, tau_r, tau_f, t0)	Functional form of pulse in frequency domain with the amplitude, rise time, fall time, and time offset allowed to float.
`twopoletime`(A, tau_r, tau_f, t0)	Functional form of pulse in time domain with the amplitude, rise time, fall time, and time offset allowed to float

calcchi2(model)¶

Function to calculate the reduced chi square

Parameters:	model : ndarray Array corresponding to pulse function (twopole or onepole) evaluated at the optimum values
Returns:	chi2 : float The reduced chi squared statistic

fit_falltimes(pulse, lgcdouble=False, errscale=1, guess=None, taurise=None, lgcfullrtn=False, lgcplot=False)¶

Function to do the fit

Parameters:	pulse : ndarray Time series traces to be fit lgcdouble : bool, optional If False, the twopole fit is done, if True, the one pole fit it done. Note, if True, the user must provide the value of taurise. errscale : float or int, optional A scale factor for the psd. Ex: if fitting an average, the errscale should be set to the number of traces used in the average guess : tuple, optional Guess of initial values for fit, must be the same size as the model being used for fit. If lgcdouble is True, then the order should be (ampguess, tauriseguess, taufallguess, t0guess). If lgcdouble is False, then the order should be (ampguess, taufallguess, t0guess). taurise : float, optional The value of the rise time of the pulse if the single pole function is being use for fit lgcfullrtn : bool, optional If False, only the best fit parameters are returned. If True, the errors in the fit parameters, the covariance matrix, and chi squared statistic are returned as well. lgcplot : bool, optional If True, diagnostic plots are returned.
Returns:	variables : tuple The best fit parameters errors : tuple The corresponding fit errors for the best fit parameters cov : ndarray The convariance matrix returned from the fit chi2 : float The reduced chi squared statistic evaluated at the optimum point of the fit
Raises:	ValueError if length of guess does not match the number of parameters needed in fit

onepole(A, tau_f, t0)¶

Functional form of pulse in time domain with the amplitude, fall time, and time offset allowed to float, and the rise time held constant

Parameters:	A : float Amplitude of pulse tau_f : float Fall time of two-pole pulse t0 : float Time offset of two pole pulse
Returns:	pulse : ndarray, complex Array of amplitude values as a function of freuqncy

residuals(params)¶

Function ot calculate the weighted residuals to be minimized

Parameters:	params : tuple Tuple containing fit parameters
Returns:	z1d : ndarray Array containing residuals per frequency bin. The complex data is flatted into single array

twopole(A, tau_r, tau_f, t0)¶

Functional form of pulse in frequency domain with the amplitude, rise time, fall time, and time offset allowed to float. This is meant to be a private function

Parameters:	A : float Amplitude of pulse tau_r : float Rise time of two-pole pulse tau_f : float Fall time of two-pole pulse t0 : float Time offset of two pole pulse
Returns:	pulse : ndarray, complex Array of amplitude values as a function of frequency

twopoletime(A, tau_r, tau_f, t0)¶

Functional form of pulse in time domain with the amplitude, rise time, fall time, and time offset allowed to float

Parameters:	A : float Amplitude of pulse tau_r : float Rise time of two-pole pulse tau_f : float Fall time of two-pole pulse t0 : float Time offset of two pole pulse
Returns:	pulse : ndarray Array of amplitude values as a function of time

class qetpy.core._fitting.MuonTailFit(psd, fs)¶

Bases: object

This class provides the user with a fitting routine to estimate the thermal muon tail fall time.

Methods

`calcchi2`(model)	Function to calculate the chi square
`fitmuontail`(signal[, lgcfullrtn, errscale])	Function to do the fit
`muontailfcn`(A, tau)	Functional form of a thermal muon tail in time domain with the amplitude and fall time allowed to float.
`residuals`(params)	Function to calculate the weighted residuals to be minimized.

calcchi2(model)¶

Function to calculate the chi square

Parameters:	model : ndarray Array corresponding to pulse function evaluated at the fitted values
Returns:	chi2 : float The chi squared statistic

fitmuontail(signal, lgcfullrtn=False, errscale=1)¶

Function to do the fit

Parameters:

signal: ndarray: Time series traces to be fit
lgcfullrtn : bool, optional: If False, only the best fit parameters are returned. If True, the errors in the fit parameters, the covariance matrix, and chi squared statistic are returned as well.
errscale : float or int, optional: A scale factor for the psd. Ex: if fitting an average, the errscale should be set to the number of traces used in the average

Returns:

variables : tuple: The best fit parameters
errors : tuple: The corresponding fit errors for the best fit parameters
cov : ndarray: The convariance matrix returned from the fit
chi2 : float: The chi squared statistic evaluated at the fit

muontailfcn(A, tau)¶

Functional form of a thermal muon tail in time domain with the amplitude and fall time allowed to float.

Parameters:	A : float Amplitude of pulse tau : float Fall time of muon tail
Returns:	pulse : ndarray Array of amplitude values as a function of time

residuals(params)¶

Function to calculate the weighted residuals to be minimized.

Parameters:	params : tuple Tuple containing fit parameters
Returns:	z1d : ndarray Array containing residuals per frequency bin. The complex data is flatted into single array.

qetpy.core._iv module¶

class qetpy.core._iv.IV(dites, dites_err, vb, vb_err, rload, rload_err, chan_names, normalinds=None)¶

Bases: object

Class for creating the IV curve and calculating various values, such as the normal resistance, the resistance of the TES, the power, etc., as well as the corresponding errors. This class supports data for multple bath temperatures, multiple channels, and multiple bias points.

Note: If different bath temperatures have different numbers of bias points (iters), then the user should pad the end of the arrays with NaN so that the data can be put into an ndarray and loaded into this class.

Attributes:

dites : ndarray: The current read out by the electronics
dites_err : ndarray: The error in the current read out by the electronics
vb : ndarray: The bias voltage (vb = qet bias * rshunt)
vb_err : ndarray: The corresponding error in the bias voltage
rload : scalar, ndarray: The load resistance, this can be scalar if using the same rload for all values. If 1-dimensional, then this should be the load resistance for each channel. If 2-dimensional, this should be the load resistance for each bath temperature and each bias point, where the shape is (ntemps, nch). If 3-dimensional, then this should be with shape (ntemps, nch, niters)
rload_err : scalar, ndarray: The corresponding error in the load resistance, should be the same type as rload
chan_names : array_like: Array of strings corresponding to the names of each channel in the data. Should have the same length as the nch axis in dites
ioff : ndarray: The current offset calculated from the fit, shape (ntemps, nch)
ioff_err : ndarray: The corresponding error in the current offset
rfit : ndarray: The total resistance (rnorm + rload) from the fit, shape (ntemps, nch)
rfit_err : ndarray: The corresponding error in the fit resistance
rnorm : ndarray: The normal resistance of the TES, using the fit, shape (ntemps, nch)
rnorm_err : ndarray: The corresponding error in the normal resistance
ites : ndarray: The calculated current through the TES, shape (ntemps, nch, niters)
ites_err : ndarray: The corresponding error in the current through the TES
r0 : ndarray: The calculated resistance of the TES, shape (ntemps, nch, niters)
r0_err : ndarray: The corresponding error in the resistance of the TES
ptes : ndarray: The calculated power of the TES, shape (ntemps, nch, niters)
ptes_err : ndarray: The corresponding error in the power of the TES

Methods

`calc_iv`()	Method to calculate the IV curve for the intialized object.
`plot_all_curves`([temps, chans, showfit, …])	Function to plot the IV, resistance, and power curves for the data in an IV object.
`plot_iv`([temps, chans, showfit, lgcsave, …])	Function to plot the IV curves for the data in an IV object.
`plot_pv`([temps, chans, lgcsave, savepath, …])	Function to plot the power curves for the data in an IV object.
`plot_rv`([temps, chans, lgcsave, savepath, …])	Function to plot the resistance curves for the data in an IV object.

calc_iv()¶: Method to calculate the IV curve for the intialized object. Calculates the power and resistance of each bias point, as well as saving the fit parameters from the fit to the normal points and the calculated normal reistance from these points.

plot_all_curves(temps='all', chans='all', showfit=True, lgcsave=False, savepath='', savename='')¶

Function to plot the IV, resistance, and power curves for the data in an IV object.

Parameters:

temps : string, array_like, int, optional: Which bath temperatures to plot. Setting to “all” plots all of them. Can also set to a subset of bath temperatures, or just one
chans : string, array_like, int, optional: Which bath temperatures to plot. Setting to “all” plots all of them. Can also set to a subset of bath temperatures, or just one
showfit : boolean, optional: Boolean flag to also plot the linear fit to the normal data
lgcsave : boolean, optional: Boolean flag to save the plot
savepath : string, optional: Path to save the plot to, saves it to the current directory by default
savename : string, optional: Name to append to the plot file name, if saving

plot_iv(temps='all', chans='all', showfit=True, lgcsave=False, savepath='', savename='')¶

Function to plot the IV curves for the data in an IV object.

Parameters:

temps : string, array_like, int, optional: Which bath temperatures to plot. Setting to “all” plots all of them. Can also set to a subset of bath temperatures, or just one
chans : string, array_like, int, optional: Which bath temperatures to plot. Setting to “all” plots all of them. Can also set to a subset of bath temperatures, or just one
showfit : boolean, optional: Boolean flag to also plot the linear fit to the normal data
lgcsave : boolean, optional: Boolean flag to save the plot
savepath : string, optional: Path to save the plot to, saves it to the current directory by default
savename : string, optional: Name to append to the plot file name, if saving

plot_pv(temps='all', chans='all', lgcsave=False, savepath='', savename='')¶

Function to plot the power curves for the data in an IV object.

Parameters:

temps : string, array_like, int, optional: Which bath temperatures to plot. Setting to “all” plots all of them. Can also set to a subset of bath temperatures, or just one
chans : string, array_like, int, optional: Which bath temperatures to plot. Setting to “all” plots all of them. Can also set to a subset of bath temperatures, or just one
lgcsave : boolean, optional: Boolean flag to save the plot
savepath : string, optional: Path to save the plot to, saves it to the current directory by default
savename : string, optional: Name to append to the plot file name, if saving

plot_rv(temps='all', chans='all', lgcsave=False, savepath='', savename='')¶

Function to plot the resistance curves for the data in an IV object.

Parameters:

temps : string, array_like, int, optional: Which bath temperatures to plot. Setting to “all” plots all of them. Can also set to a subset of bath temperatures, or just one
chans : string, array_like, int, optional: Which bath temperatures to plot. Setting to “all” plots all of them. Can also set to a subset of bath temperatures, or just one
lgcsave : boolean, optional: Boolean flag to save the plot
savepath : string, optional: Path to save the plot to, saves it to the current directory by default
savename : string, optional: Name to append to the plot file name, if saving

qetpy.core._noise module¶

qetpy.core._noise.foldpsd(psd, fs)¶

Return the one-sided version of the inputted two-sided psd.

Parameters:	psd : ndarray A two-sided psd to be converted to one-sided fs : float The sample rate used for the psd
Returns:	f : ndarray The frequencies corresponding to the outputted one-sided psd psd_folded : ndarray The one-sided (folded over) psd corresponding to the inputted two-sided psd

qetpy.core._noise.calc_psd(x, fs=1.0, folded_over=True)¶

Return the PSD of an n-dimensional array, assuming that we want the PSD of the last axis.

Parameters:

x : array_like: Array to calculate PSD of.
fs : float, optional: Sample rate of the data being taken, assumed to be in units of Hz.
folded_over : bool, optional: Boolean value specifying whether or not the PSD should be folded over. If True, then the symmetric values of the PSD are multiplied by two, and we keep only the positive frequencies. If False, then the entire PSD is saved, including positive and negative frequencies. Default is to fold over the PSD.

Returns:

f : ndarray: Array of sample frequencies
psd : ndarray: Power spectral density of ‘x’

qetpy.core._noise.gen_noise(psd, fs=1.0, ntraces=1)¶

Function to generate noise traces with random phase from a given PSD. The PSD calculated from the generated noise traces should be the equivalent to the inputted PSD as the number of traces goes to infinity.

Parameters:	psd : ndarray The two-sided power spectral density that will be used to generate the noise. fs : float, optional Sample rate of the data being taken, assumed to be in units of Hz. ntraces : int, optional The number of noise traces that should be generated. Default is 1.
Returns:	noise : ndarray An array containing all of the generated noise traces from the inputted PSD. Has shape (ntraces, len(psd)).

class qetpy.core._noise.Noise(traces, fs, channames, tracegain=1.0, fname=None, time=None)¶

Bases: object

This class allows the user to calculate the power spectral densities of signals from detectors, study correlations, and decouple the intrinsic noise from cross channel correlated noise.

Attributes:

traces : ndarray: Array of the traces to use in the noise analysis. Should be shape (# of traces, # of channels, # of bins)
fs : float: The digitization rate of the data in Hz.
channames : list: A list of strings that name each of the channels.
time : ndarray: The time values for each bin in each trace.
fname : str: The file name of the data, this will be used when saving the file.
tracegain : float: The factor that traces should be divided by to convert the units to Amps. If rawtraces already has units of Amps, then this should be set to 1.0
freqs : ndarray: The frequencies that correspond to each value in the spectral densities
psd : ndarray: The power spectral density of the data in A^2/Hz
realpsd : ndarray: The real power spectral density of the data in A^2/Hz
imagpsd : ndarray: The imaginary power spectral density of the data in A^2/Hz
corrcoeff : ndarray: The array of the correlation coefficients between each of the channels
uncorrnoise : ndarray: The uncorrelated noise psd in A^2/Hz
corrnoise : ndarray: The correlated noise psd in A^2/Hz
realcsd : ndarray: The real part of the cross spectral density in A^2/Hz
imagcsd : ndarray: The imaginary part of the cross spectral density in A^2/Hz
realcsdstd : ndarray: The standard deviation of the real part of the cross spectral density at each frequency
imagcsdstd : ndarray: The standard deviation of the imaginary part of the cross spectral density at each frequency
csd : ndarray: The cross spectral density of the traces
chandict : dict: A dictionary that stores the channel number for each channel name.

Methods

`calculate_corrcoeff`()	Calculates the correlations between channels as a function of frequency.
`calculate_csd`()	Calculates the csd for each channel in traces.
`calculate_psd`()	Calculates the psd for each channel in traces.
`calculate_uncorr_noise`()	Calculates the uncorrelated and correlated total noise.
`plot_corrcoeff`([lgcsmooth, nwindow, …])	Function to plot the cross channel correlation coefficients.
`plot_csd`([whichcsd, lgcreal, lgcsave, savepath])	Function to plot the cross channel noise spectrum referenced to the TES line in units of Amperes^2/Hz
`plot_decorrelatednoise`([lgcoverlay, …])	Function to plot the de-correlated noise spectrum referenced to the TES line in units of Amperes/sqrt(Hz) from fitted parameters calculated calculate_deCorrelated_noise
`plot_psd`([lgcoverlay, lgcsave, savepath])	Function to plot the noise spectrum referenced to the TES line in units of Amperes/sqrt(Hz).
`plot_reim_psd`([lgcsave, savepath])	Function to plot the real vs imaginary noise spectrum referenced to the TES line in units of Amperes/sqrt(Hz).
`remove_trace_slope`()	Function to remove the slope from each trace.
`save`(path)	Saves the noise object as a pickle file

calculate_corrcoeff()¶: Calculates the correlations between channels as a function of frequency. Stores results in self.corrcoeff

calculate_csd()¶: Calculates the csd for each channel in traces. Stores csd in self.csd

calculate_psd()¶: Calculates the psd for each channel in traces. Stores psd in self.psd

calculate_uncorr_noise()¶: Calculates the uncorrelated and correlated total noise.

plot_corrcoeff(lgcsmooth=True, nwindow=7, lgcsave=False, savepath=None)¶

Function to plot the cross channel correlation coefficients. Since there are typically few traces, the correlations are often noisy. a savgol_filter is used to smooth out some of the noise

Parameters:	lgcsmooth : boolean, optional If True, a savgol_filter will be used when plotting. nwindow : int, optional the number of bins used for the window in the savgol_filter lgcsave : boolean, optional If True, the figure is saved in the user provided directory savepath : str, optional Absolute path for the figure to be saved

plot_csd(whichcsd=['01'], lgcreal=True, lgcsave=False, savepath=None)¶

Function to plot the cross channel noise spectrum referenced to the TES line in units of Amperes^2/Hz

Parameters:

whichcsd : list, optional: a list of strings, where each element of the list refers to the pair of indices of the desired csd plot
lgcreal : boolean, optional: If True, the Re(csd) is plotted. If False, the Im(csd) is plotted
lgcsave : boolean, optional: If True, the figure is saved in the user provided directory
savepath : str, optional: Absolute path for the figure to be saved

plot_decorrelatednoise(lgcoverlay=False, lgcdata=True, lgcuncorrnoise=True, lgccorrelated=False, lgcsum=False, lgcsave=False, savepath=None)¶

Function to plot the de-correlated noise spectrum referenced to the TES line in units of Amperes/sqrt(Hz) from fitted parameters calculated calculate_deCorrelated_noise

Parameters:

lgcoverlay : boolean, optional: If True, de-correlated for all channels are overlayed in a single plot, If False, the noise for each channel is plotted in a seperate subplot
lgcdata : boolean, optional: Only applies when lgcoverlay = False. If True, the csd data is plotted
lgcuncorrnoise : boolean, optional: Only applies when lgcoverlay = False. If True, the de-correlated noise is plotted
lgccorrelated : boolean, optional: Only applies when lgcoverlay = False. If True, the correlated component of the fitted noise is plotted
lgcsum : boolean, optional: Only applies when lgcoverlay = False. If True, the sum of the fitted de-correlated noise and and correlated noise is plotted
lgcsave : boolean, optional: If True, the figure is saved in the user provided directory
savepath : str, optional: Absolute path for the figure to be saved

plot_psd(lgcoverlay=True, lgcsave=False, savepath=None)¶

Function to plot the noise spectrum referenced to the TES line in units of Amperes/sqrt(Hz).

Parameters:	lgcoverlay : boolean, optional If True, psd’s for all channels are overlayed in a single plot, If False, each psd for each channel is plotted in a seperate subplot lgcsave : boolean, optional If True, the figure is saved in the user provided directory savepath : str, optional Absolute path for the figure to be saved

plot_reim_psd(lgcsave=False, savepath=None)¶

Function to plot the real vs imaginary noise spectrum referenced to the TES line in units of Amperes/sqrt(Hz). This is done to check for thermal muon tails making it passed the quality cuts

Parameters:	lgcsave : boolean, optional If True, the figure is saved in the user provided directory savepath : str, optional Absolute path for the figure to be saved

remove_trace_slope()¶: Function to remove the slope from each trace. self.traces is changed to be the slope subtracted traces.

save(path)¶

Saves the noise object as a pickle file

Parameters:	path : str Path where the noise object should be saved.