Plot logcat from android device in ubuntu

run.py

import pyqtgraph as pg
import time

plt = pg.plot()

def update(data):
    plt.plot(data, clear=True)

class Thread(pg.QtCore.QThread):
    newData = pg.QtCore.Signal(object)
    def run(self):
        while True:
            data = pg.np.random.normal(size=100)
            # do NOT plot data from here!
            self.newData.emit(data)
            time.sleep(0.05)

thread = Thread()
thread.newData.connect(update)
thread.start()
pg.QtGui.QApplication.exec_()

import sys, os
import numpy as np
from matplotlib import pyplot as plt
from collections import deque
from subprocess import call, Popen, PIPE, STDOUT

MAXLEN = 50
MAX_AMPLITUDE = 1300

# class that holds rotation data for N samples
class RotationData:
  # constr
  def __init__(self, maxLen):
    #self.x = deque([0.0]*MAXLEN)
    self.values = deque()
    self.maxLen = MAXLEN
 
  # ring buffer
  def addToBuf(self, buf, val):
    if len(buf) < self.maxLen:
      buf.append(val)
    else:
      buf.popleft()
      buf.append(val)
 
  # add data
  def add(self, data):
    #self.addToBuf(self.x, xValue)
    self.addToBuf(self.values, data)

  #clear the data
  def clear(self):
      #self.x = deque([0.0]*MAXLEN)
      self.values.clear()

# plot class
class RotationPlot:
  # constr
  def __init__(self, rotationData):
    # set plot to animated
    plt.ion()
    # Create a figure of size 8x6 inches, 80 dots per inch
    plt.figure(figsize=(8, 6), dpi=100)

    # Create a new subplot from a grid of 1x1
    plt.subplot(1,1,1)
    #self.xline, = plt.plot(rotationData.x)
    self.yline, = plt.plot(rotationData.values)
    plt.xlim(0, MAXLEN)
    plt.ylim(-MAX_AMPLITUDE, MAX_AMPLITUDE)
 
  # update plot
  def update(self, rotationData, x):
    #self.xline.set_ydata(RotationData.x)
    self.yline.set_xdata(np.arange(x))
    self.yline.set_ydata(rotationData.values)
    plt.draw()

print "Starting \n"
try:
    retcodeLaunchApp = call(["adb", "logcat"])
    if retcodeLaunchApp < 0:
        print >>sys.stderr, "Child was terminated by signal", -retcode
    else:
        print "Balance app correctly launched \n"
        p = Popen('android-sdk-macosx/platform-tools/adb logcat -v raw', stdout = PIPE, 
                stderr = STDOUT, shell = True)
        # plot parameters
        rotationData = RotationData(MAXLEN)
        rotationPlot = RotationPlot(rotationData)
        x = 0
        while True:
            try:
                line = p.stdout.readline()
                if not line: break
                if line.startswith('ROT:'):
                    rot = line.partition('ROT:')
                    if x >= MAXLEN:
                        rotationData.clear()
                        x = 0
                    rotationData.add(rot[2])
                    x = x+1
                    rotationPlot.update(rotationData, x)
            except KeyboardInterrupt:
                print 'exiting'
                break      
except OSError as e:
    print >>sys.stderr, "Execution failed:", e
    sys.exit(2)



sys.exit(0)

copied from this discussion https://groups.google.com/forum/#!topic/pyqtgraph/19aWCvy9Enk