Modal fitting¶
Circle fitting¶
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class
cued_datalogger.analysis.circle_fit.
CircleFitWidget
(parent: QWidget = None, flags: Union[Qt.WindowFlags, Qt.WindowType] = Qt.WindowFlags())¶ Bases:
PyQt5.QtWidgets.QWidget
Methods
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error_function
(parameters)¶ The error function for least squares fitting.
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refresh_nyquist_plot
()¶ Clear the nyquist plot and add the items back in.
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refresh_transfer_function_plot
()¶ Clear the transfer function plot and add the items back in.
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sdof_get_parameters
()¶ Fit a SDOF peak to the data with a least squares fit, using values from the current peak as a first guess.
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sdof_peak_with_offset
(w, wn, zn, an, phi)¶ An SDOF modal peak fitted to the data using the geometric circle.
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set_selected_channels
(selected_channels)¶ Update which channels are plotted.
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class
cued_datalogger.analysis.circle_fit.
CircleFitToolbox
(parent=None)¶ Bases:
cued_datalogger.api.toolbox.Toolbox
The Toolbox for the CircleFitWidget.
This Toolbox contains the tools for controlling the circle fit. It has two tabs: ‘Transfer Function’, for tools relating to the construction of a transfer function, and ‘Autofit Controls’, which contains tools for controlling how the circle is fit to the data.
Attributes
sig_construct_transfer_fn (pyqtSignal) The signal emitted when a new transfer function is to be constructed. sig_show_transfer_fn (pyqtSignal(bool)) The signal emitted when the visibility of the transfer function is changed. Format (visible). Methods
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cued_datalogger.analysis.circle_fit.
fit_circle_to_data
(x, y)¶ Fit a geometric circle to the data given in x, y.
Parameters: x : ndarray
y : ndarray
Returns: x0 : float
The x-coordinate of the centre of the circle.
y0 : float
The y-coordinate of the centre of the circle.
R0 : float
The radius of the circle.
Notes
This function solves a standard eigenvector formulation of the circle fit problem. See [R11] for the derivation.
References
[R11] (1, 2) Maia, N.M.M., Silva, J.M.M. et al, Theoretical and Experimental Modal Analysis, p221, Research Studies Press, 1997.