#!/usr/bin/env python
# coding: utf-8

# # Live-updating plots with zmq, bqplot, and widgets

# Start a simple zmq data publishing service, as a demo:

# In[1]:


get_ipython().run_cell_magic('writefile', 'publisher.py', "\nimport time\nimport pickle\n\nimport numpy as np\nimport zmq\n\nsize = 100\nscale = 100\nurl = 'tcp://127.0.0.1:5555'\n\ndef main():\n    ctx = zmq.Context.instance()\n    pub = ctx.socket(zmq.PUB)\n    pub.bind(url)\n    while True:\n        data = np.cumsum(np.random.randn(size)  * scale)\n        md = {\n            'shape': data.shape,\n            'dtype': data.dtype,\n        }\n        pub.send_multipart([\n                pickle.dumps(md, pickle.HIGHEST_PROTOCOL),\n                data,\n        ])\n        time.sleep(1)\n\nif __name__ == '__main__':\n    main()\n")


# In[2]:


from subprocess import Popen
publisher = Popen([sys.executable, 'publisher.py'])


# Make an ipywidgets-based plot with bqplot:

# In[5]:


import numpy as np
import bqplot as bq

size = 100
scale = 100.
np.random.seed(0)
x_data = np.arange(size)
y_data = np.cumsum(np.random.randn(size)  * scale)

x_sc = bq.LinearScale()
y_sc = bq.LinearScale()

ax_x = bq.Axis(label='X', scale=x_sc, grid_lines='solid')
ax_y = bq.Axis(label='Y', scale=y_sc, orientation='vertical', grid_lines='solid')

line = bq.Lines(x=x_data, y=y_data, scales={'x': x_sc, 'y': y_sc})
fig = bq.Figure(axes=[ax_x, ax_y], marks=[line], title='Live Updates!')
fig


# Subscribe to our data-publisher, updating 

# In[4]:


import pickle

def subscribe(url):
    ctx = zmq.Context.instance()
    s = ctx.socket(zmq.SUB)
    s.connect('tcp://127.0.0.1:5555')
    s.subscribe = b''
    while True:
        pmd, buf = s.recv_multipart()
        md = pickle.loads(pmd)
        a = np.frombuffer(buf, dtype=md['dtype']).reshape(md['shape'])
        # setting line.y updates the plot above
        line.y = a


from threading import Thread

subscriber = Thread(target=subscribe, args=('tcp://127.0.0.1:5555',))
subscriber.start()