def mean_alpha(alphas, surfaces):
    return np.average(alphas, axis=0, weights=surfaces)
Fetches a url's HTML and extracts all image sources in an <img> tag.
dataset/ETHPy150Open python-acoustics/python-acoustics/acoustics/room.py/mean_alpha--crossover with--dataset/ETHPy150Open unlimitedlabs/orchestra/simple_workflow/v1/crawl.py/find_images