import time, struct
import numpy as np
import matplotlib.pyplot as plt

path = 'E:/big_ass.rdd'
ptr = 0
np_ptr = 0
buff = np.zeros([2,2000000], np.float64)
t = time.time()
with open(path, 'rb') as f:
    f.seek(1024)
    while True:
        b = f.read(16)
        if b:
            buff[:, np_ptr] = struct.unpack('dd', b)
            np_ptr+=1
            ptr += 16*9999
            f.seek(ptr)
        else:
            break
plt.plot(buff[0, :np_ptr], buff[1, :np_ptr])
plt.show()
print(buff[:, :np_ptr])