# Random location [200, 200] as an example.
loc_x = loc_y = 200

ydata = get_magnitude_hist_block(loc_x, loc_y)
ydata = ydata / np.linalg.norm(ydata)

xdata = range(len(ydata))
bucket_names = np.tile(np.arange(N_BUCKETS), BLOCK_SIZE * BLOCK_SIZE)

assert len(ydata) == N_BUCKETS * (BLOCK_SIZE * BLOCK_SIZE)
assert len(bucket_names) == len(ydata)

plt.figure(figsize=(10, 3))
plt.bar(xdata, ydata, align='center', alpha=0.8, width=0.9)
plt.xticks(xdata, bucket_names * 20, rotation=90)
plt.xlabel('Direction buckets')
plt.ylabel('Magnitude')
plt.grid(ls='--', color='k', alpha=0.1)
plt.title("HOG of block at [%d, %d]" % (loc_x, loc_y))
plt.tight_layout()