Source code for pyfda.plot_widgets.plot_phi

# -*- coding: utf-8 -*-
#
# This file is part of the pyFDA project hosted at https://github.com/chipmuenk/pyfda
#
# Copyright © pyFDA Project Contributors
# Licensed under the terms of the MIT License
# (see file LICENSE in root directory for details)
"""
Widget for plotting phase frequency response phi(f)
"""
import logging
logger = logging.getLogger(__name__)

from pyfda.libs.compat import QCheckBox, QWidget, QComboBox, QHBoxLayout, QFrame, pyqtSignal

import numpy as np

import pyfda.filterbroker as fb
from pyfda.pyfda_rc import params
from pyfda.plot_widgets.mpl_widget import MplWidget
from pyfda.libs.pyfda_lib import calc_Hcomplex, pprint_log
from pyfda.libs.pyfda_qt_lib import qget_cmb_box

classes = {'Plot_Phi':'\u03C6(f)'} #: Dict containing class name : display name

[docs]class Plot_Phi(QWidget): # incoming, connected in sender widget (locally connected to self.process_sig_rx() ) sig_rx = pyqtSignal(object) # outgoing, distributed via plot_tab_widget sig_tx = pyqtSignal(object) def __init__(self, parent): super(Plot_Phi, self).__init__(parent) self.needs_calc = True # recalculation of filter function necessary self.needs_draw = True # plotting neccessary (e.g. log instead of lin) self.tool_tip = "Phase frequency response" self.tab_label = "\u03C6(f)" # phi(f) self._construct_UI() #------------------------------------------------------------------------------
[docs] def process_sig_rx(self, dict_sig=None): """ Process signals coming from the navigation toolbar and from sig_rx """ logger.debug("Processing {0} | needs_calc = {1}, visible = {2}"\ .format(dict_sig, self.needs_calc, self.isVisible())) if dict_sig['sender'] == __name__: logger.debug("Stopped infinite loop\n{0}".format(pprint_log(dict_sig))) return if self.isVisible(): if 'data_changed' in dict_sig or 'home' in dict_sig or self.needs_calc: self.draw() self.needs_calc = False self.needs_draw = False elif 'view_changed' in dict_sig or self.needs_draw: self.update_view() self.needs_draw = False # elif ('ui_changed' in dict_sig and dict_sig['ui_changed'] == 'resized')\ # or self.needs_redraw: # self.redraw() else: if 'data_changed' in dict_sig: self.needs_calc = True elif 'view_changed' in dict_sig: self.needs_draw = True
# elif 'ui_changed' in dict_sig and dict_sig['ui_changed'] == 'resized': # self.needs_redraw = True #------------------------------------------------------------------------------ def _construct_UI(self): """ Intitialize the widget, consisting of: - Matplotlib widget with NavigationToolbar - Frame with control elements """ self.cmbUnitsPhi = QComboBox(self) units = ["rad", "rad/pi", "deg"] scales = [1., 1./ np.pi, 180./np.pi] for unit, scale in zip(units, scales): self.cmbUnitsPhi.addItem(unit, scale) self.cmbUnitsPhi.setObjectName("cmbUnitsA") self.cmbUnitsPhi.setToolTip("Set unit for phase.") self.cmbUnitsPhi.setCurrentIndex(0) self.cmbUnitsPhi.setSizeAdjustPolicy(QComboBox.AdjustToContents) self.chkWrap = QCheckBox("Wrapped Phase", self) self.chkWrap.setChecked(False) self.chkWrap.setToolTip("Plot phase wrapped to +/- pi") layHControls = QHBoxLayout() layHControls.addWidget(self.cmbUnitsPhi) layHControls.addWidget(self.chkWrap) layHControls.addStretch(10) #---------------------------------------------------------------------- # ### frmControls ### # # This widget encompasses all control subwidgets #---------------------------------------------------------------------- self.frmControls = QFrame(self) self.frmControls.setObjectName("frmControls") self.frmControls.setLayout(layHControls) #---------------------------------------------------------------------- # ### mplwidget ### # # main widget, encompassing the other widgets #---------------------------------------------------------------------- self.mplwidget = MplWidget(self) self.mplwidget.layVMainMpl.addWidget(self.frmControls) self.mplwidget.layVMainMpl.setContentsMargins(*params['wdg_margins']) self.setLayout(self.mplwidget.layVMainMpl) self.init_axes() self.draw() # initial drawing #---------------------------------------------------------------------- # GLOBAL SIGNALS & SLOTs #---------------------------------------------------------------------- self.sig_rx.connect(self.process_sig_rx) #---------------------------------------------------------------------- # LOCAL SIGNALS & SLOTs #---------------------------------------------------------------------- self.chkWrap.clicked.connect(self.draw) self.cmbUnitsPhi.currentIndexChanged.connect(self.unit_changed) self.mplwidget.mplToolbar.sig_tx.connect(self.process_sig_rx) #------------------------------------------------------------------------------
[docs] def init_axes(self): """ Initialize and clear the axes - this is only called once """ if len(self.mplwidget.fig.get_axes()) == 0: # empty figure, no axes self.ax = self.mplwidget.fig.subplots() self.ax.get_xaxis().tick_bottom() # remove axis ticks on top self.ax.get_yaxis().tick_left() # remove axis ticks right
#------------------------------------------------------------------------------
[docs] def unit_changed(self): """ Unit for phase display has been changed, emit a 'view_changed' signal and continue with drawing. """ self.sig_tx.emit({'sender':__name__, 'view_changed':'plot_phi'}) self.draw()
#------------------------------------------------------------------------------
[docs] def calc_resp(self): """ (Re-)Calculate the complex frequency response H(f) """ # calculate H_cplx(W) (complex) for W = 0 ... 2 pi: self.W, self.H_cmplx = calc_Hcomplex(fb.fil[0], params['N_FFT'], wholeF=True) # replace nan and inf by finite values, otherwise np.unwrap yields # an array full of nans self.H_cmplx = np.nan_to_num(self.H_cmplx)
#------------------------------------------------------------------------------
[docs] def draw(self): """ Main entry point: Re-calculate \|H(f)\| and draw the figure """ self.calc_resp() self.update_view()
#------------------------------------------------------------------------------
[docs] def update_view(self): """ Draw the figure with new limits, scale etc without recalculating H(f) """ self.unitPhi = qget_cmb_box(self.cmbUnitsPhi, data=False) f_S2 = fb.fil[0]['f_S'] / 2. #========= select frequency range to be displayed ===================== #=== shift, scale and select: W -> F, H_cplx -> H_c F = self.W * f_S2 / np.pi if fb.fil[0]['freqSpecsRangeType'] == 'sym': # shift H and F by f_S/2 H = np.fft.fftshift(self.H_cmplx) F -= f_S2 elif fb.fil[0]['freqSpecsRangeType'] == 'half': # only use the first half of H and F H = self.H_cmplx[0:params['N_FFT']//2] F = F[0:params['N_FFT']//2] else: # fb.fil[0]['freqSpecsRangeType'] == 'whole' # use H and F as calculated H = self.H_cmplx y_str = r'$\angle H(\mathrm{e}^{\mathrm{j} \Omega})$ in ' if self.unitPhi == 'rad': y_str += 'rad ' + r'$\rightarrow $' scale = 1. elif self.unitPhi == 'rad/pi': y_str += 'rad' + r'$ / \pi \;\rightarrow $' scale = 1./ np.pi else: y_str += 'deg ' + r'$\rightarrow $' scale = 180./np.pi fb.fil[0]['plt_phiLabel'] = y_str fb.fil[0]['plt_phiUnit'] = self.unitPhi if self.chkWrap.isChecked(): phi_plt = np.angle(H) * scale else: phi_plt = np.unwrap(np.angle(H)) * scale #--------------------------------------------------------- self.ax.clear() # need to clear, doesn't overwrite line_phi, = self.ax.plot(F, phi_plt) #--------------------------------------------------------- self.ax.set_title(r'Phase Frequency Response') self.ax.set_xlabel(fb.fil[0]['plt_fLabel']) self.ax.set_ylabel(y_str) self.ax.set_xlim(fb.fil[0]['freqSpecsRange']) self.redraw()
#------------------------------------------------------------------------------
[docs] def redraw(self): """ Redraw the canvas when e.g. the canvas size has changed """ self.mplwidget.redraw()
#------------------------------------------------------------------------------ def main(): import sys from pyfda.libs.compat import QApplication app = QApplication(sys.argv) mainw = Plot_Phi(None) app.setActiveWindow(mainw) mainw.show() sys.exit(app.exec_()) if __name__ == "__main__": main() # module test using python -m pyfda.plot_widgets.plot_phi