Python- How to generate new array formed with rows of initial 1-d array with different calculations each

Question

I have a 1-d array "arr" arr = np.array([1, 2, 3, 4, 5]) and I generated a list from degree=3 deg = list(range(1, degree+1))

I want a matrix with shape(arr, degree) that is from from the rows:

[arr^d0...] // [1,2,3,4,5]
[arr^d1...] // [1,4,9,16,25]
[arr^d2...] // [1,8,27,64,125]

I understand I should use a for loop but I don't know-how.

Chris · Accepted Answer · 2020-12-07 05:35:39Z

1

Let numpy broadcast it for you:

(arr[:, None] ** deg).T

Output:

array([[  1,   2,   3,   4,   5],
       [  1,   4,   9,  16,  25],
       [  1,   8,  27,  64, 125]])

answered Dec 7, 2020 at 5:35

Chris

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Comments

Piyush Singh · Accepted Answer · 2020-12-07 05:34:46Z

0

This should do the trick:

arr = np.array([1, 2, 3, 4, 5])
degree = 3
deg = list(range(1, degree+1))
A = np.stack([arr**i for i in deg])
print(A)

answered Dec 7, 2020 at 5:34

Piyush Singh

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