Signal

The signal class, Signal, is the base class from which specialized signals can be created and to which mixins with additional functionality can be added, the current available mixins are the following:

Filter mixins, BesselFiltersMixin, ButterworthFiltersMixin, EllipticFiltersMixin, to filter the signal by different methods also providing the possibility to implement your own filters via the FiltersMixin base class.

State levels mixin, StateLevelsMixin, to calculate the logical state levels of the signal.

Edges mixin, EdgesMixin, to obtain the edges of the signal.

A detailed example of an specialized signal that ships with the package is the voltage signal, VoltageSignal, its implementation can be checked for details on how to use the base signal class.

An example of its usage is shown in the following code snippet:

import numpy as np
import signal_edges.signal as ses

# Create timestamps in seconds for the signal, the horizontal axis.
signal_timestamps = np.linspace(start=0, stop=160, num=160, endpoint=False)
# Create voltages in seconds for the signal, the vertical axis.
signal_voltages = np.asarray([0, 0, 0, 0, 5, 5, 5, 5, 5, 5] * (160 // 10))
# Create signal with the previous values, and seconds and volts as units.
signal = ses.VoltageSignal(signal_timestamps, signal_voltages, "s", "V")

# Plot signal to file.
signal.signal_plot("signal.png")

Which creates the following signal:

../_images/000_example_signal.png — The generated signal in the code snippet.

class Signal

Base class for signal, meant to be derived to create specialized signals on which to add mixins from this package with additional functionality.

A signal consists in two 1xN arrays, where N is the number of values, one with the values for the horizontal axis and another one with the values for the vertical axis. The number of values in each array must be the same, and additionally the values of the horizontal axis must satisfy the requirement x[n] < x[n+1] for all their values.

Note

For simplicity, the Numpy arrays provided to this class are copied internally, changes outside this classs to the arrays provided will not reflect on the internal ones, use the relevant getters and setters to reflect this changes on the internal arrays.

__init__(hvalues, vvalues, *args, hunits=None, vunits=None, **kwargs)

The constructor for the signal class.

Parameters:

hvalues (ndarray[Any, dtype[float64]]) – A 1xN array with the values of the horizontal axis to copy for the signal.
vvalues (ndarray[Any, dtype[float64]]) – A 1xN array with the values of the vertical axis to copy for the signal.
hunits (Optional[Units]) – The units of the values of the horizontal axis for plots, defaults to no units.
vunits (Optional[Units]) – The units of the values of the vertical axis for plots, defaults to no units.

property _logger: Logger

Getter for the logger for the signal, use this from the derived class to print information to the logger of the package. For information on how to configure the package logger refer to get_logger().

Return type:: Logger
Returns:: The logger.

property _hv: ndarray[Any, dtype[float64]]

Getter for the values of the horizontal axis.

Return type:: ndarray[Any, dtype[float64]]
Returns:: A 1xN array with the values of the horizontal axis.

property _vv: ndarray[Any, dtype[float64]]

Getter for the values of the vertical axis.

Return type:: ndarray[Any, dtype[float64]]
Returns:: A 1xN array with the values of the vertical axis.

property _hunits: Units

Getter for the units of the values of the horizontal axis.

Return type:: Units
Returns:: The units.

property _vunits: Units

Getter for the units of the values of the vertical axis.

Return type:: Units
Returns:: The units.

signal_plot(path, *args, begin=None, end=None, munits=0, **kwargs)

Performs a plot of the signal.

Parameters:

path (str) – The path where to store the plot, see Plotter.plot().
args – Additional arguments to pass to the plotting function, see Plotter.plot().
begin (Optional[float]) – The begin value of the horizontal axis where the plot starts, see Plotter.plot().
end (Optional[float]) – The end value of the horizontal axis where the plot ends, see Plotter.plot().
munits (float) – Margin units for the plot, see Plotter.plot().
kwargs – Additional keyword arguments to pass to the plotting function, see Plotter.plot().

Return type:

Self

Returns:

Instance of the class.

exception SignalError: Signal exception class.

Voltage Signal

The voltage signal class, VoltageSignal, is a specialized signal for timestamps and voltages, shipped as part of python-signal-edges and used throughout the examples in the documentation. It is also available to use from the user code.

class VoltageSignal

Bases: ButterworthFiltersMixin, EllipticFiltersMixin, BesselFiltersMixin, StateLevelsMixin, EdgesMixin, Signal

Predefined implementation of a Signal that represents an analog voltage signal as captured, for example, by an oscilloscope, data recorder or similar.

The horizontal axis of the signal contains the timestamps values and the vertical axis of the signal contains the voltage values, in miliseconds or seconds and in milivolts or volts respectively.

__init__(timestamps, voltages, timestamp_unit_id=None, voltage_unit_id=None)

Class constructor.

Parameters:

timestamps (ndarray[Any, dtype[float64]]) – The timestamp values for the signal.
voltages (ndarray[Any, dtype[float64]]) – The voltage values for the signal.
timestamp_unit_id (Optional[Literal['ms', 's']]) – An identifier for the timestamp units, can be ignored if not plotting.
voltage_unit_id (Optional[Literal['mV', 'V']]) – An identifier for the voltage units, can be ignored if not plotting.

property timestamps: ndarray[Any, dtype[float64]]

Getter for the timestamps.

Return type:: ndarray[Any, dtype[float64]]
Returns:: The timestamps.

property voltages: ndarray[Any, dtype[float64]]

Getter for the voltages

Return type:: ndarray[Any, dtype[float64]]
Returns:: The voltages.

property timestamp_units: Units

Getter for the timestamp units.

Return type:: Units
Returns:: The timestamps units.

property voltage_units: Units

Getter for the voltage units.

Return type:: Units
Returns:: The voltage units.

exception VoltageSignalError: Voltage signal exception class.