Add PyQtGraph random walk without datetime

Author: s-celles

samples/sample_pyqtgraph_no_datetime.py

@@ -0,0 +1,69 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+"""
+This example demonstrates a random walk with pyqtgraph.
+"""
+
+import sys
+import numpy as np
+import pyqtgraph as pg
+from pyqtgraph.Qt import QtGui, QtCore
+from numpy_buffer import RingBuffer #  https://github.com/scls19fr/numpy-buffer
+
+class RandomWalkPlot:
+    def __init__(self, win):
+        #self.plot = pg.plot()
+        self.plot = win.addPlot(title="Updating plot")
+        
+        self.ptr = 0
+        
+        #pen = 'r'
+        pen = pg.mkPen('b', style=QtCore.Qt.SolidLine)
+        self.curve = self.plot.plot(pen=pen, symbol='+')
+        self.timer = QtCore.QTimer()
+        self.timer.timeout.connect(self.update)
+        self.timer.start(50)
+        
+        self.value = 1000 # initial value
+        N = 100 # number of elements into circular buffer
+        
+        self.data_y = RingBuffer(N, self.value)
+        
+
+    def update(self):
+        self.value += np.random.uniform(-1, 1)
+
+        self.data_y.append(self.value)
+        
+        self.curve.setData(y=self.data_y) #  size is increasing up to N
+        #self.curve.setData(y=self.data_y.all[::-1]) #  size is always N
+        
+        #if self.ptr == 0:
+        #    self.plot.enableAutoRange('xy', False)  ## stop auto-scaling after the first data set is plotted
+        #self.ptr += 1
+
+def main():
+    #QtGui.QApplication.setGraphicsSystem('raster')
+    app = QtGui.QApplication(sys.argv)
+
+    #mw = QtGui.QMainWindow()
+    #mw.resize(800,800)
+
+    pg.setConfigOption('background', 'w')
+    pg.setConfigOption('foreground', 'k')
+
+    win = pg.GraphicsWindow(title="Basic plotting examples")
+    win.resize(1000, 600)
+    win.setWindowTitle('plot')
+
+    # Enable antialiasing for prettier plots
+    pg.setConfigOptions(antialias=True)
+    
+    upl = RandomWalkPlot(win)
+    
+    ## Start Qt event loop unless running in interactive mode or using pyside.
+    if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
+        QtGui.QApplication.instance().exec_()
+
+if __name__ == '__main__':
+	main()