def add_plot(self, name, units):
# legend
legend = QwtLegend()
legend.setFrameStyle(Qt.QFrame.Box | Qt.QFrame.Sunken)
legend.setItemMode(QwtLegend.ClickableItem)
# plot
plot = QwtPlot(self)
plot.setTitle(name.upper())
plot.setObjectName(name)
plot.setCanvasBackground(Qt.Qt.white)
plot.setAxisTitle(QwtPlot.xBottom, "time [s]")
plot.insertLegend(legend, QwtPlot.RightLegend)
plot.time = deque(maxlen=MAX_LENGTH)
plot.data = []
plot.curves = []
for i, unit in enumerate(units):
position = QwtPlot.yLeft if i == 0 else QwtPlot.yRight
curve = QwtPlotCurve(LEGENDS[unit])
curve.setPen(Qt.QPen(self.next_color(), 2))
curve.setYAxis(position)
curve.attach(plot)
plot.enableAxis(position)
plot.setAxisTitle(position, unit)
plot.curves.append(curve)
plot.data.append(deque(maxlen=MAX_LENGTH))
self.vertical_layout.addWidget(plot)
self._plots[name] = plot