#!/usr/bin/env python # /*########################################################################## # # Copyright (c) 2016-2020 European Synchrotron Radiation Facility # # Permission is hereby granted, free of charge, to any person obtaining a copy # of this software and associated documentation files (the "Software"), to deal # in the Software without restriction, including without limitation the rights # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell # copies of the Software, and to permit persons to whom the Software is # furnished to do so, subject to the following conditions: # # The above copyright notice and this permission notice shall be included in # all copies or substantial portions of the Software. # # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN # THE SOFTWARE. # # ###########################################################################*/ """This script is a simple example of how to create a :class:`~silx.gui.plot.PlotWindow` with a custom :class:`~silx.gui.plot.actions.PlotAction` added to the toolbar. The action computes the FFT of all curves and plots their amplitude spectrum. It also performs the reverse transform. This example illustrates: - how to create a checkable action - how to store user info with a curve in a PlotWindow - how to modify the graph title and axes labels - how to add your own icon as a PNG file See shiftPlotAction.py for a simpler example with more basic comments. """ __authors__ = ["P. Knobel"] __license__ = "MIT" __date__ = "27/06/2017" import numpy import os import sys from silx.gui import qt from silx.gui.plot import PlotWindow from silx.gui.plot.actions import PlotAction # Custom icon # make sure there is a "fft.png" file saved in the same folder as this script scriptdir = os.path.dirname(os.path.realpath(__file__)) my_icon = os.path.join(scriptdir, "fft.png") class FftAction(PlotAction): """QAction performing a Fourier transform on all curves when checked, and reverse transform when unchecked. :param plot: PlotWindow on which to operate :param parent: See documentation of :class:`QAction` """ def __init__(self, plot, parent=None): PlotAction.__init__( self, plot, icon=qt.QIcon(my_icon), text="FFT", tooltip="Perform Fast Fourier Transform on all curves", triggered=self.fftAllCurves, checkable=True, parent=parent, ) def _rememberGraphLabels(self): """Store labels and title as attributes""" self.original_title = self.plot.getGraphTitle() self.original_xlabel = self.plot.getXAxis().getLabel() self.original_ylabel = self.plot.getYAxis().getLabel() def fftAllCurves(self, checked=False): """Get all curves from our PlotWindow, compute the amplitude spectrum using a Fast Fourier Transform, replace all curves with their amplitude spectra. When un-checking the button, do the reverse transform. :param checked: Boolean parameter signaling whether the action has been checked or unchecked. """ allCurves = self.plot.getAllCurves(withhidden=True) if checked: # remember original labels self._rememberGraphLabels() # change them self.plot.setGraphTitle("Amplitude spectrum") self.plot.getXAxis().setLabel("Frequency") self.plot.getYAxis().setLabel("Amplitude") else: # restore original labels self.plot.setGraphTitle(self.original_title) self.plot.getXAxis().setLabel(self.original_xlabel) self.plot.getYAxis().setLabel(self.original_ylabel) self.plot.clearCurves() for curve in allCurves: x = curve.getXData() y = curve.getYData() legend = curve.getName() info = curve.getInfo() if info is None: info = {} if checked: # FAST FOURIER TRANSFORM fft_y = numpy.fft.fft(y) # amplitude spectrum A = numpy.abs(fft_y) # sampling frequency (samples per X unit) Fs = len(x) / (max(x) - min(x)) # frequency array (abscissa of new curve) F = [k * Fs / len(x) for k in range(len(A))] # we need to store the complete transform (complex data) to be # able to perform the reverse transform. info["complex fft"] = fft_y info["original x"] = x # plot the amplitude spectrum self.plot.addCurve(F, A, legend="FFT of " + legend, info=info) else: # INVERSE FFT fft_y = info["complex fft"] # we keep only the real part because we know the imaginary # part is 0 (our original data was real numbers) y1 = numpy.real(numpy.fft.ifft(fft_y)) # recover original info x1 = info["original x"] legend1 = legend[7:] # remove "FFT of " # remove restored data from info dict for key in ["complex fft", "original x"]: del info[key] # plot the original data self.plot.addCurve(x1, y1, legend=legend1, info=info) self.plot.resetZoom() app = qt.QApplication([]) sys.excepthook = qt.exceptionHandler plotwin = PlotWindow(control=True) toolbar = qt.QToolBar("My toolbar") plotwin.addToolBar(toolbar) myaction = FftAction(plotwin) toolbar.addAction(myaction) # x range: 0 -- 10 (1000 points) x = numpy.arange(1000) * 0.01 twopi = 2 * numpy.pi # Sum of sine functions with frequencies 3, 20 and 42 Hz y1 = ( numpy.sin(twopi * 3 * x) + 1.5 * numpy.sin(twopi * 20 * x) + 2 * numpy.sin(twopi * 42 * x) ) # Cosine with frequency 7 Hz and phase pi / 3 y2 = numpy.cos(twopi * 7 * (x - numpy.pi / 3)) # 5 periods of square wave, amplitude 2 y3 = numpy.zeros_like(x) for i in [0, 2, 4, 6, 8]: y3[i * len(x) // 10 : (i + 1) * len(x) // 10] = 2 plotwin.addCurve(x, y1, legend="sin") plotwin.addCurve(x, y2, legend="cos") plotwin.addCurve(x, y3, legend="square wave") plotwin.setGraphTitle("Original data") plotwin.getYAxis().setLabel("amplitude") plotwin.getXAxis().setLabel("time") plotwin.show() app.exec() sys.excepthook = sys.__excepthook__