[solved] how to speed-up huge data in an ascii file ?

[paul18fr]

Thanks Gribouillis,

Your advice helped me a lot; based on your example, I modified it a bit in order to concatenate different data with different sizes.

import numpy as np
import os

path = str(os.getcwd())

# Creating a numpy array
n = 10 # 1_000_000# 10_000_000
M1 = np.random.random((n, 3))

m = 100
M2 = np.random.random((m, 10))

# Opening a file
with open(path + '/file.txt','w+') as f :
    
    #appending M1
    np.savetxt(f, M1, fmt='X=%.18e, Y=%.18e, Z=%.18e', header = 'blabla')
    # add of an intermediate line
    f.write("####### a comment is added\n")
    np.savetxt(f, M2)

Thanks

Paul