You have some logic issues here. First off, I wouldn't be updating the plot in the same function that is updating the data values. Assuming that "loop_start()" is asynchronous, the update frequency for it is likely to be entirely different from the Animation update frequency. So, just have that function do updates. You should also declare x, y, and z as globals in that function so that the reassignment of those arrays persist properly.
Your list comprehension prior to concatenating uses a variable "x", which is likely causing the current error that you see. Change that name to something else. Lastly, I implore you to use "set_data()" like in the original example, rather than calling plot() repeatedly. Cheers! Ben Root On Tue, Sep 29, 2015 at 2:05 PM, Shakthi Kannan <[email protected]> wrote: > Hi, > > I was able to get past the error, and I am now trying to add a > callback to receive values from a queue, add it to the existing poly > line, and render the same using matplotlib. The code snippet is shown > below: > > === BEGIN === > > import matplotlib as mpl > from mpl_toolkits.mplot3d import Axes3D > import numpy as np > import matplotlib.pyplot as plt > import matplotlib.animation as animation > import sys > import paho.mqtt.client as mqtt > > def update_line(num, x, y, z, l): > print x, y, z > l, = ax.plot(x, y, z, label='Line') > return l, > > def on_connect(client, userdata, flags, rc): > print("Connected with result code "+str(rc)) > client.subscribe("hello/world") > > def on_message(client, userdata, msg): > data = msg.payload > print(msg.topic+" "+str(msg.payload)) > point = np.asarray([float(x) for x in data.split()]) > print point > x=np.concatenate((x,[point[0]])) > y=np.concatenate((y,[point[1]])) > z=np.concatenate((z,[point[2]])) > l, = ax.plot(x, y, z, label='Line') > return l, > > fig = plt.figure() > ax = fig.gca(projection='3d') > ax.set_xlabel('X') > ax.set_ylabel('Y') > ax.set_zlabel('Z') > > x = np.array([1.0, 2.0, 3.0]) > print type(x) > y = np.array([4.0, 7.0, 8.0]) > z = np.array([6.0, 9.0, 5.0]) > > l, = ax.plot(x, y, z, label='Line') > ax.legend() > > client = mqtt.Client() > client.on_connect = on_connect > client.on_message = on_message > client.connect_async("localhost", 1883, 60) > client.loop_start() > > line_ani = animation.FuncAnimation(fig, update_line, 25, fargs=(x, y, > z, l), interval=2000, blit=True) > > plt.show() > > === END === > > I now hit the following error: > > === ERROR === > > $ python mat-3.py > <type 'numpy.ndarray'> > [ 1. 2. 3.] [ 4. 7. 8.] [ 6. 9. 5.] > Connected with result code 0 > [ 1. 2. 3.] [ 4. 7. 8.] [ 6. 9. 5.] > [ 1. 2. 3.] [ 4. 7. 8.] [ 6. 9. 5.] > [ 1. 2. 3.] [ 4. 7. 8.] [ 6. 9. 5.] > hello/world 34.56 15.912 0.72 > [ 34.56 15.912 0.72 ] > Exception in thread Thread-1: > Traceback (most recent call last): > File "/usr/lib/python2.7/threading.py", line 810, in __bootstrap_inner > self.run() > File "/usr/lib/python2.7/threading.py", line 763, in run > self.__target(*self.__args, **self.__kwargs) > File "/usr/local/lib/python2.7/dist-packages/paho/mqtt/client.py", > line 2287, in _thread_main > self.loop_forever() > File "/usr/local/lib/python2.7/dist-packages/paho/mqtt/client.py", > line 1261, in loop_forever > rc = self.loop(timeout, max_packets) > File "/usr/local/lib/python2.7/dist-packages/paho/mqtt/client.py", > line 811, in loop > rc = self.loop_read(max_packets) > File "/usr/local/lib/python2.7/dist-packages/paho/mqtt/client.py", > line 1073, in loop_read > rc = self._packet_read() > File "/usr/local/lib/python2.7/dist-packages/paho/mqtt/client.py", > line 1475, in _packet_read > rc = self._packet_handle() > File "/usr/local/lib/python2.7/dist-packages/paho/mqtt/client.py", > line 1943, in _packet_handle > return self._handle_publish() > File "/usr/local/lib/python2.7/dist-packages/paho/mqtt/client.py", > line 2118, in _handle_publish > self._handle_on_message(message) > File "/usr/local/lib/python2.7/dist-packages/paho/mqtt/client.py", > line 2274, in _handle_on_message > self.on_message(self, self._userdata, message) > File "mat-3.py", line 23, in on_message > x=np.concatenate((x,[point[0]])) > ValueError: zero-dimensional arrays cannot be concatenated > > [ 1. 2. 3.] [ 4. 7. 8.] [ 6. 9. 5.] > [ 1. 2. 3.] [ 4. 7. 8.] [ 6. 9. 5.] > [ 1. 2. 3.] [ 4. 7. 8.] [ 6. 9. 5.] > > ... > > === END === > > Is there a better way to re-render the plot after receiving data? > > Thanks! > > SK > > -- > Shakthi Kannan > http://www.shakthimaan.com > > > ------------------------------------------------------------------------------ > _______________________________________________ > Matplotlib-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/matplotlib-users >
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