How to add noise to the first index of array,with the number of iterations the max number iteration is 2.

I want to add a noise in range (1, max_iterator) to rows in order, for example:

• add 0.788 to row 1st
• add 1.233 to row 2nd
• add 0.788 to row 3rd
• add 1.233 to row 4th
• and 0.788 to row 5th
• and so on

I’ve tried to use this code but it doesn’t work

a = np.array([[858,833,123],
             [323,542,927],
             [938,361,271],
             [679,272,451]])
noise = np.random.normal(loc=0, scale=0.1, size=1)
max_iter = 2
for i in range(max_iter):
    for j in range(len(a)):
        a[i][0] = np.clip(a[i][0] + noise, a_min=0.0, a_max=None)
print(a)

>Solution :

You can do:

# you'll need to cast the array as floats rather ints to add other floats
a = np.array([[858,833,123],
             [323,542,927],
             [938,361,271],
             [679,272,451]]).astype(float)

n = 2

# create n random values
noise = np.random.normal(loc=0, scale=0.1, size=n)

# loop through rows in steps of n
for i in range(0, a.shape[0], n):
    a[i:i + n, 0] = np.clip(a[i:i + 1, 0] + noise, a_min=0.0, a_max=None)