errordriftcalc.py

class IDriftCalculator

Bases: ABC

Interface (abstract base class) for applying a function to cause a sensor array measurement to drift (normally over time). The initialiser for the concrete implementation of this class specifies the function parameters and a unified method is provided to calculate the drift based on the input.

abstractmethod calc_drift(drift_var)

Abstract method. Used to calculate the drift function based on the input drift variable (useually the time steps).

Parameters:

drift_var (np.ndarray) – Array of values (normally time steps) that are used to calculate the drift errors.

Returns:

np.ndarray – Array of drift errors having the same shape as the input drift_var array.

class DriftConstant(offset)

Bases: IDriftCalculator

Class for applying a constant drift error over time.

Implements the IDriftCalculator interface.

__init__(offset)

Parameters:

offset (float) – Constant drift offset.

calc_drift(drift_var)

Calculates the drift errors based on the input drift variable array.

Parameters:

drift_var (np.ndarray) – Array of values (normally time steps) that are used to calculate the drift errors.

Returns:

np.ndarray – Array of drift errors having the same shape as the input drift_var array.

class DriftLinear(slope, offset=0.0)

Bases: IDriftCalculator

Class for applying a linear drift error over time.

Implements the IDriftCalculator interface.

__init__(slope, offset=0.0)

Parameters:

• slope (float) – Slope of the drift error function.

• offset (float, optional) – Offset (intercept) of the drift error function, by default 0.0.

calc_drift(drift_var)

Calculates the drift errors based on the input drift variable array.

Parameters:

drift_var (np.ndarray) – Array of values (normally time steps) that are used to calculate the drift errors.

Returns:

np.ndarray – Array of drift errors having the same shape as the input drift_var array.

class DriftPolynomial(coeffs)

Bases: IDriftCalculator

Class for applying a polynomial drift error over time. The coefficients of the polynomial are specified with a numpy array from constant term to highest power.

Implements the IDriftCalculator interface.

__init__(coeffs)

Parameters:

coeffs (np.ndarray) – Array of polynomial coefficients from constant to highest power.

calc_drift(drift_var)

Calculates the drift errors based on the input drift variable array.

Parameters:

drift_var (np.ndarray) – Array of values (normally time steps) that are used to calculate the drift errors.

Returns:

np.ndarray – Array of drift errors having the same shape as the input drift_var array.