Fast Cameras

import numpy as np
import matplotlib.pyplot as plt
import pandas as pd
import requests

from PIL import Image
from io import BytesIO
from IPython.display import Image as DispImage

shot_no = 33969

SpeedCamera = True


try:
    url = "http://golem.fjfi.cvut.cz/shots/%i/Diagnostics/FastExCameras/plasma_film.png"%(shot_no)
    image = requests.get(url)
    img = Image.open(BytesIO(image.content)).convert('L') #'L','1'

    data = np.asanyarray(img)

    r = []
    for i in range(data.shape[1]):
        a=0
        b=0
        for j in range(336):
            a += data[j,i]*j
            b += data[j,i]
        r.append((a/b))
    duration = (len(r)/(1200*96))*1e3
#     print(duration)
    camera_time = np.linspace(0, duration, len(r))
    r_camera = pd.Series(r, index = camera_time)-150
    
    fig = plt.figure()
    ax = r_camera.plot(label = 'Speed Camera')
    plt.legend()
    ax.set(ylim=(-85, 85), title='Horizontal plasma position #%i'%shot_no,ylabel='$\Delta$r visible radiation', xlabel = 'Time [ms]')
    ax.axhline(y=0, color='k', ls='--', lw=1, alpha=0.4)
    fig.savefig('SpeedCamera')
except OSError:
    SpeedCamera = False

/home/golem/anaconda3/lib/python3.7/site-packages/ipykernel_launcher.py:29: RuntimeWarning: invalid value encountered in long_scalars

fig, ax = plt.subplots()
img = Image.open(BytesIO(image.content))
ax.imshow(img)

<matplotlib.image.AxesImage at 0x7feab7eb90d0>