Create a vector length n with n entries 'x'

Question

Example:

n = 5
x = 3.5
Output:
array([3.5, 3.5, 3.5, 3.5, 3.5])

My code:

import numpy as np
def init_all_x(n, x):
    np.all = [x]*n
    return np.all
init_all_x(5, 3.5)

My question:

Why init_all_x(5, 3.5).shape cannot run?

If my code is wrong, what is the correct code? Thank you!

Does this answer your question? [NumPy array initialization (fill with identical values)](https://stackoverflow.com/questions/5891410/numpy-array-initialization-fill-with-identical-values) — mkrieger1, Dec 02 '22 at 11:29

score 0 · Accepted Answer · answered Dec 02 '22 at 07:58

0

you can use np.ones

arr = np.ones(5)*3.5

answered Dec 02 '22 at 07:58

Maen

score 0 · Answer 2 · answered Dec 02 '22 at 08:46

0

Simple approach with numpy.repeat:

n = 5
x = 3.5
a = np.repeat(x, n)

Output:

array([3.5, 3.5, 3.5, 3.5, 3.5])

answered Dec 02 '22 at 08:46

mozway

score 0 · Answer 3 · answered Dec 02 '22 at 08:50

0

For your requirement, no need to use Numpy lib, you can code like this:

def init_all_x(n, x):
    return [x]*n

p = init_all_x(5, 3.5)
print(p)

Output:

[3.5, 3.5, 3.5, 3.5, 3.5]

answered Dec 02 '22 at 08:50

Mansour Torabi

score 0 · Answer 4 · answered Dec 02 '22 at 09:11

0

Numpy has a dedicated function np.full to do just this:

n = 5
x = 3.5

out = np.full(n, x)
# array([3.5, 3.5, 3.5, 3.5, 3.5])

answered Dec 02 '22 at 09:11

Chrysophylaxs

4 Answers4