dgpost.transform.circuit_utils package
Submodules
dgpost.transform.circuit_utils.circuit_components module
- dgpost.transform.circuit_utils.circuit_components.create_parameter(name, bounds, unit)
Creates a dictionary with keys name, bounds and unit
- Parameters
name (
str) – name of the parameterbounds (
tuple[float,float]) – default bounds of the parameterunit (
str) – SI unit of the parameter
- Returns
dictionary containing the input values
- Return type
dict
- class dgpost.transform.circuit_utils.circuit_components.Component
Bases:
objectA component stores information needed for the fitting.
- static get_symbol()
Unique symbol used to identify the component in the circuit string
The symbol can only contain letters, i.e. a-z, A-Z
- Return type
str
- static get_parameters(name)
returns the parameter(s) that describe the component
A parameter is a dictionary with the keys: name, bounds and unit. The name of the parameter should be based on the symbol. It can also contain any character except a whitespace. The bounds are given as a tuple with the lower (lb) and upper bounds (ub) like (lb, ub). The unit needs to be recognised by pint
- Parameters
name (
str) – name of the component in the circuit string, made out of the symbol with an additional digit.- Returns
The parameters that describes the component. A parameter is a dictionary with 3 keys: ‘name’, ‘bounds’ and ‘unit’
- Return type
list[dict]
- static calc_impedance(param, name, freq)
Calculates the impedance of the component
- Parameters
param (
dict[str,float]) – dictionary of parameter values with the name as the keyname (
str) – the name of the componentfreq (
array) – the frequencies at which the impedance should be calculated
- Returns
numpy array with the complex impedance of the component for the given frequencies
- Return type
np.array
- class dgpost.transform.circuit_utils.circuit_components.Resistor
Bases:
dgpost.transform.circuit_utils.circuit_components.Componentdefines a resistor
- static get_symbol()
Unique symbol used to identify the component in the circuit string
The symbol can only contain letters, i.e. a-z, A-Z
- static get_parameters(name)
returns the parameter(s) that describe the component
A parameter is a dictionary with the keys: name, bounds and unit. The name of the parameter should be based on the symbol. It can also contain any character except a whitespace. The bounds are given as a tuple with the lower (lb) and upper bounds (ub) like (lb, ub). The unit needs to be recognised by pint
- Parameters
name – name of the component in the circuit string, made out of the symbol with an additional digit.
- Returns
The parameters that describes the component. A parameter is a dictionary with 3 keys: ‘name’, ‘bounds’ and ‘unit’
- Return type
list[dict]
- static calc_impedance(param, name, freq)
Calculates the impedance of the component
- Parameters
param – dictionary of parameter values with the name as the key
name – the name of the component
freq – the frequencies at which the impedance should be calculated
- Returns
numpy array with the complex impedance of the component for the given frequencies
- Return type
np.array
- class dgpost.transform.circuit_utils.circuit_components.Capacitor
Bases:
dgpost.transform.circuit_utils.circuit_components.Componentdefines a capacitor
- static get_symbol()
Unique symbol used to identify the component in the circuit string
The symbol can only contain letters, i.e. a-z, A-Z
- static get_parameters(name)
returns the parameter(s) that describe the component
A parameter is a dictionary with the keys: name, bounds and unit. The name of the parameter should be based on the symbol. It can also contain any character except a whitespace. The bounds are given as a tuple with the lower (lb) and upper bounds (ub) like (lb, ub). The unit needs to be recognised by pint
- Parameters
name – name of the component in the circuit string, made out of the symbol with an additional digit.
- Returns
The parameters that describes the component. A parameter is a dictionary with 3 keys: ‘name’, ‘bounds’ and ‘unit’
- Return type
list[dict]
- static calc_impedance(param, name, freq)
Calculates the impedance of the component
- Parameters
param – dictionary of parameter values with the name as the key
name – the name of the component
freq – the frequencies at which the impedance should be calculated
- Returns
numpy array with the complex impedance of the component for the given frequencies
- Return type
np.array
- class dgpost.transform.circuit_utils.circuit_components.CPE
Bases:
dgpost.transform.circuit_utils.circuit_components.Componentdefines a constant phase element
- static get_symbol()
Unique symbol used to identify the component in the circuit string
The symbol can only contain letters, i.e. a-z, A-Z
- static get_parameters(name)
returns the parameter(s) that describe the component
A parameter is a dictionary with the keys: name, bounds and unit. The name of the parameter should be based on the symbol. It can also contain any character except a whitespace. The bounds are given as a tuple with the lower (lb) and upper bounds (ub) like (lb, ub). The unit needs to be recognised by pint
- Parameters
name – name of the component in the circuit string, made out of the symbol with an additional digit.
- Returns
The parameters that describes the component. A parameter is a dictionary with 3 keys: ‘name’, ‘bounds’ and ‘unit’
- Return type
list[dict]
- static calc_impedance(param, name, freq)
Calculates the impedance of the component
- Parameters
param – dictionary of parameter values with the name as the key
name – the name of the component
freq – the frequencies at which the impedance should be calculated
- Returns
numpy array with the complex impedance of the component for the given frequencies
- Return type
np.array
- class dgpost.transform.circuit_utils.circuit_components.Warburg
Bases:
dgpost.transform.circuit_utils.circuit_components.Componentdefines a semi-infinite Warburg element
- static get_symbol()
Unique symbol used to identify the component in the circuit string
The symbol can only contain letters, i.e. a-z, A-Z
- static get_parameters(name)
returns the parameter(s) that describe the component
A parameter is a dictionary with the keys: name, bounds and unit. The name of the parameter should be based on the symbol. It can also contain any character except a whitespace. The bounds are given as a tuple with the lower (lb) and upper bounds (ub) like (lb, ub). The unit needs to be recognised by pint
- Parameters
name – name of the component in the circuit string, made out of the symbol with an additional digit.
- Returns
The parameters that describes the component. A parameter is a dictionary with 3 keys: ‘name’, ‘bounds’ and ‘unit’
- Return type
list[dict]
- static calc_impedance(param, name, freq)
Calculates the impedance of the component
- Parameters
param – dictionary of parameter values with the name as the key
name – the name of the component
freq – the frequencies at which the impedance should be calculated
- Returns
numpy array with the complex impedance of the component for the given frequencies
- Return type
np.array
- class dgpost.transform.circuit_utils.circuit_components.WarburgOpen
Bases:
dgpost.transform.circuit_utils.circuit_components.Componentdefines a finite-space Warburg element
- static get_symbol()
Unique symbol used to identify the component in the circuit string
The symbol can only contain letters, i.e. a-z, A-Z
- static get_parameters(name)
returns the parameter(s) that describe the component
A parameter is a dictionary with the keys: name, bounds and unit. The name of the parameter should be based on the symbol. It can also contain any character except a whitespace. The bounds are given as a tuple with the lower (lb) and upper bounds (ub) like (lb, ub). The unit needs to be recognised by pint
- Parameters
name – name of the component in the circuit string, made out of the symbol with an additional digit.
- Returns
The parameters that describes the component. A parameter is a dictionary with 3 keys: ‘name’, ‘bounds’ and ‘unit’
- Return type
list[dict]
- static calc_impedance(param, name, freq)
Calculates the impedance of the component
- Parameters
param – dictionary of parameter values with the name as the key
name – the name of the component
freq – the frequencies at which the impedance should be calculated
- Returns
numpy array with the complex impedance of the component for the given frequencies
- Return type
np.array
- class dgpost.transform.circuit_utils.circuit_components.WarburgShort
Bases:
dgpost.transform.circuit_utils.circuit_components.Componentdefines a finite-length Warburg element
- static get_symbol()
Unique symbol used to identify the component in the circuit string
The symbol can only contain letters, i.e. a-z, A-Z
- static get_parameters(name)
returns the parameter(s) that describe the component
A parameter is a dictionary with the keys: name, bounds and unit. The name of the parameter should be based on the symbol. It can also contain any character except a whitespace. The bounds are given as a tuple with the lower (lb) and upper bounds (ub) like (lb, ub). The unit needs to be recognised by pint
- Parameters
name – name of the component in the circuit string, made out of the symbol with an additional digit.
- Returns
The parameters that describes the component. A parameter is a dictionary with 3 keys: ‘name’, ‘bounds’ and ‘unit’
- Return type
list[dict]
- static calc_impedance(param, name, freq)
Calculates the impedance of the component
- Parameters
param – dictionary of parameter values with the name as the key
name – the name of the component
freq – the frequencies at which the impedance should be calculated
- Returns
numpy array with the complex impedance of the component for the given frequencies
- Return type
np.array
dgpost.transform.circuit_utils.circuit_parser module
- dgpost.transform.circuit_utils.circuit_parser.parse_circuit(circ)
Extended Backus–Naur form (EBNF) parser for a circuit string.
Implements an extended Backus–Naur form (EBNF) to parse a string containing a description of a circuit.
- The syntax of the EBNF is given by:
circuit = element | element-circuit
element = component | parallel
parallel = p(circuit {,circuit})
component = a circuit component defined in
circuit_components
So to put elements in series connect them through ‘-’ Parallel elements are created by p(…,… ,…)
To use a component in the circuit string use its symbol. The symbol can be followed by a digit to differentiate similar components. Already implemented circuit elements are located in
dgpost.transform.circuit_utils.circuit_components.py.From this a function is generated and which evaluates the impedance of the circuit.
- Parameters
circ (
str) – String describing a circuit- Return type
Tuple[list[dict],Callable[[dict,ndarray],ndarray]]- Returns
param_info – list of used parameter. For more information about parameters look in
circuit_componentscalculate
- dgpost.transform.circuit_utils.circuit_parser.fit_routine(opt_func, fit_guess, bounds, repeat=1)
Fitting routine which uses scipy least_squares and minimize.
Least_squares is a good fitting method but will get stuck in local minima. For this reason, the Nelder-Mead-Simplex algorithm is used to get out of these local minima. The fitting routine is inspired by Relaxis 3 fitting procedure. More information about it can be found on page 188 of revision 1.25 of Relaxis User Manual. https://www.rhd-instruments.de/download/manuals/relaxis_manual.pdf
Open issue is estimate the errors of the parameters. For further information look: - https://github.com/andsor/notebooks/blob/master/src/nelder-mead.md - https://math.stackexchange.com/questions/2447382/nelder-mead-function-fit-error-estimation-via-surface-fit - https://stats.stackexchange.com/questions/424073/calculate-the-uncertainty-of-a-mle
- Parameters
opt_func (
Callable[[list],float]) – function that gets minimizedfit_guess (
list[float]) – initial guess for minimizationbounds (
list[tuple]) – bounds of the fitting parametersrepeat (
int) – how many times the least squares and minimize step gets repeated
- Returns
opt_result – the result of the optimization from the last step of Nelder-Mead.
- Return type
scipy.optimize.OptimizeResult