def __init__(self, *args):
QwtPlot.__init__(self, *args)
self.setTitle("Frequency Response of a 2<sup>nd</sup>-order System")
self.setCanvasBackground(Qt.darkBlue)
# legend
legend = QwtLegend()
legend.setFrameStyle(QFrame.Box | QFrame.Sunken)
self.insertLegend(legend, QwtPlot.BottomLegend)
# grid
QwtPlotGrid.make(plot=self,
enableminor=(True, False),
color=Qt.darkGray)
# axes
self.enableAxis(QwtPlot.yRight)
self.setAxisTitle(QwtPlot.xBottom, "\u03c9/\u03c9<sub>0</sub>")
self.setAxisTitle(QwtPlot.yLeft, "Amplitude [dB]")
self.setAxisTitle(QwtPlot.yRight, "Phase [\u00b0]")
self.setAxisMaxMajor(QwtPlot.xBottom, 6)
self.setAxisMaxMinor(QwtPlot.xBottom, 10)
self.setAxisScaleEngine(QwtPlot.xBottom, QwtLogScaleEngine())
# curves
self.curve1 = QwtPlotCurve.make(title="Amplitude",
linecolor=Qt.yellow,
plot=self,
antialiased=True)
self.curve2 = QwtPlotCurve.make(title="Phase",
linecolor=Qt.cyan,
plot=self,
antialiased=True)
self.dB3Marker = QwtPlotMarker.make(
label=QwtText.make(color=Qt.white,
brush=Qt.red,
weight=QFont.Light),
linestyle=QwtPlotMarker.VLine,
align=Qt.AlignRight | Qt.AlignBottom,
color=Qt.green,
width=2,
style=Qt.DashDotLine,
plot=self,
)
self.peakMarker = QwtPlotMarker.make(
label=QwtText.make(color=Qt.red,
brush=self.canvasBackground(),
weight=QFont.Bold),
symbol=QwtSymbol.make(QwtSymbol.Diamond, Qt.yellow, Qt.green,
(7, 7)),
linestyle=QwtPlotMarker.HLine,
align=Qt.AlignRight | Qt.AlignBottom,
color=Qt.red,
width=2,
style=Qt.DashDotLine,
plot=self,
)
QwtPlotMarker.make(
xvalue=0.1,
yvalue=-20.0,
align=Qt.AlignRight | Qt.AlignBottom,
label=QwtText.make(
"[1-(\u03c9/\u03c9<sub>0</sub>)<sup>2</sup>+2j\u03c9/Q]"
"<sup>-1</sup>",
color=Qt.white,
borderradius=2,
borderpen=QPen(Qt.lightGray, 5),
brush=Qt.lightGray,
weight=QFont.Bold,
),
plot=self,
)
self.setDamp(0.01)
def __init__(self, *args):
QwtPlot.__init__(self, *args)
# set plot title
self.setTitle("ImagePlot")
# set plot layout
self.plotLayout().setCanvasMargin(0)
self.plotLayout().setAlignCanvasToScales(True)
# set legend
legend = QwtLegend()
legend.setDefaultItemMode(QwtLegendData.Clickable)
self.insertLegend(legend, QwtPlot.RightLegend)
# set axis titles
self.setAxisTitle(QwtPlot.xBottom, "time (s)")
self.setAxisTitle(QwtPlot.yLeft, "frequency (Hz)")
colorMap = QwtLinearColorMap(Qt.blue, Qt.red)
interval = QwtInterval(-1, 1)
self.enableAxis(QwtPlot.yRight)
self.setAxisScale(QwtPlot.yRight, -1, 1)
self.axisWidget(QwtPlot.yRight).setColorBarEnabled(True)
self.axisWidget(QwtPlot.yRight).setColorMap(interval, colorMap)
# calculate 3 NumPy arrays
x = np.arange(-2 * np.pi, 2 * np.pi, 0.01)
y = np.pi * np.sin(x)
z = 4 * np.pi * np.cos(x) * np.cos(x) * np.sin(x)
# attach a curve
QwtPlotCurve.make(x,
y,
title="y = pi*sin(x)",
linecolor=Qt.green,
linewidth=2,
plot=self)
# attach another curve
QwtPlotCurve.make(x,
z,
title="y = 4*pi*sin(x)*cos(x)**2",
linewidth=2,
plot=self)
# attach a grid
grid = QwtPlotGrid()
grid.attach(self)
grid.setPen(QPen(Qt.black, 0, Qt.DotLine))
# attach a horizontal marker at y = 0
QwtPlotMarker.make(
label="y = 0",
linestyle=QwtPlotMarker.HLine,
align=Qt.AlignRight | Qt.AlignTop,
plot=self,
)
# attach a vertical marker at x = pi
QwtPlotMarker.make(
np.pi,
0.0,
label="x = pi",
linestyle=QwtPlotMarker.VLine,
align=Qt.AlignRight | Qt.AlignBottom,
plot=self,
)
# attach a plot image
plotImage = PlotImage("Image")
plotImage.attach(self)
plotImage.setData(
square(512, -2 * np.pi, 2 * np.pi),
(-2 * np.pi, 2 * np.pi),
(-2 * np.pi, 2 * np.pi),
)
legend.clicked.connect(self.toggleVisibility)
# replot
self.replot()
