#!/usr/bin/env python

import argparse

parser = argparse.ArgumentParser()
parser.add_argument("pvname")
parser.add_argument("height", type=int)
parser.add_argument("width", type=int)
clargs = parser.parse_args()


from matplotlib import pyplot as plt
from epics import PV


pvname = clargs.pvname
height = clargs.height
width  = clargs.width


pv = PV(pvname)
img = pv.value.reshape(height, width)

fig, ax = plt.subplots()
isp = plt.imshow(img)

def update(value=None, **kwargs):
    img = value.reshape(height, width)
    isp.set_array(img)
    plt.draw()

pv.add_callback(update)

plt.show()