Data demo — PythonQwt 0.14 Manual (original) (raw)

import random

import numpy as np from qtpy.QtCore import QSize, Qt from qtpy.QtGui import QBrush, QPen from qtpy.QtWidgets import QFrame

from qwt import ( QwtAbstractScaleDraw, QwtLegend, QwtPlot, QwtPlotCurve, QwtPlotMarker, QwtSymbol, ) from qwt.tests import utils

class DataPlot(QwtPlot): def init(self, unattended=False): QwtPlot.init(self)

    self.setCanvasBackground(Qt.white)
    self.alignScales()

    # Initialize data
    self.x = np.arange(0.0, 100.1, 0.5)
    self.y = np.zeros(len(self.x), float)
    self.z = np.zeros(len(self.x), float)

    self.setTitle("A Moving QwtPlot Demonstration")
    self.insertLegend(QwtLegend(), QwtPlot.BottomLegend)

    self.curveR = QwtPlotCurve("Data Moving Right")
    self.curveR.attach(self)
    self.curveL = QwtPlotCurve("Data Moving Left")
    self.curveL.attach(self)

    self.curveL.setSymbol(
        QwtSymbol(QwtSymbol.Ellipse, QBrush(), QPen(Qt.yellow), QSize(7, 7))
    )

    self.curveR.setPen(QPen(Qt.red))
    self.curveL.setPen(QPen(Qt.blue))

    mY = QwtPlotMarker()
    mY.setLabelAlignment(Qt.AlignRight | Qt.AlignTop)
    mY.setLineStyle(QwtPlotMarker.HLine)
    mY.setYValue(0.0)
    mY.attach(self)

    self.setAxisTitle(QwtPlot.xBottom, "Time (seconds)")
    self.setAxisTitle(QwtPlot.yLeft, "Values")

    self.startTimer(10 if unattended else 50)
    self.phase = 0.0

def alignScales(self):
    self.canvas().setFrameStyle(QFrame.Box | QFrame.Plain)
    self.canvas().setLineWidth(1)
    for axis_id in QwtPlot.AXES:
        scaleWidget = self.axisWidget(axis_id)
        if scaleWidget:
            scaleWidget.setMargin(0)
        scaleDraw = self.axisScaleDraw(axis_id)
        if scaleDraw:
            scaleDraw.enableComponent(QwtAbstractScaleDraw.Backbone, False)

def timerEvent(self, e):
    if self.phase > np.pi - 0.0001:
        self.phase = 0.0

    # y moves from left to right:
    # shift y array right and assign new value y[0]
    self.y = np.concatenate((self.y[:1], self.y[:-1]))
    self.y[0] = np.sin(self.phase) * (-1.0 + 2.0 * random.random())

    # z moves from right to left:
    # Shift z array left and assign new value to z[n-1].
    self.z = np.concatenate((self.z[1:], self.z[:1]))
    self.z[-1] = 0.8 - (2.0 * self.phase / np.pi) + 0.4 * random.random()

    self.curveR.setData(self.x, self.y)
    self.curveL.setData(self.x, self.z)

    self.replot()
    self.phase += np.pi * 0.02

def test_data(): """Data Test""" utils.test_widget(DataPlot, size=(500, 300))

if name == "main": test_data()