rolling1.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Sun May 12 20:54:18 2019

@author: martindrech
"""
# -*- coding: utf-8 -*-
"""
Various methods of drawing scrolling plots.
"""

import pyqtgraph as pg
from pyqtgraph.Qt import QtCore, QtGui
import numpy as np
from PyQt5 import QtGui
import sys

app = QtGui.QApplication(sys.argv)

win = pg.GraphicsLayoutWidget()
win.setWindowTitle('pyqtgraph example: Scrolling Plots')


# 1) Simplest approach -- update data in the array such that plot appears to scroll
#    In these examples, the array size is fixed.
p1 = win.addPlot()
p2 = win.addPlot()
#data1 = np.random.normal(size=2000)
data1 = np.zeros(1000)
curve1 = p1.plot(data1)
curve2 = p2.plot(data1)
ptr1 = 0
def update1():
    global data1, ptr1
    data1 = np.roll(data1, -1)  # shift data in the array one sample left
    data1[-1] = 5+np.random.rand()                        # (see also: np.roll)
    curve1.setData(data1)
    ptr1 += 1
    curve2.setData(data1)
    curve2.setPos(ptr1, 0)

def update():
    update1()
    
timer = pg.QtCore.QTimer()
timer.timeout.connect(update)
timer.start(50)
win.show()

## Start Qt event loop unless running in interactive mode or using pyside.
if __name__ == '__main__':
    import sys
    if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
        QtGui.QApplication.instance().exec_()