Matrix Loop with multiple vectors: Pyhton

Question

Good evening, everyone

I’m a beginner in Python and I would like your help, I did this program but the answer is in the form of several vectors or 24 vectors, and in reality I wanted only a Matrix(24,1), follows below what I did, I thank you already:

import numpy as np
import pandas as pd

ex = pd.read_excel('3.1.xlsx')
meanX1 = np.mean(ex.X1)
meanX2 = np.mean(ex.X2)
meanI = np.mean(ex.I)
stdX1 =np.std(ex.X1)
stdX2 =np.std(ex.X2)
stdI =np.std(ex.I)

for i in range(0, 25):
        aux = np.zeros([1,1])
        X1std = aux + (ex.X1[i] - meanX1)/stdX1
        print(X1std)

the answer is this with 24 vectors, I would like a column Matrix with 24 lines:

[[-0.26102763]]
[[-0.85427226]]
[[-0.85427226]]
[[-0.7059611]]
[[-0.40933879]]
[[-0.26102763]]
[[-1.00258342]]
[[-0.26102763]]
[[3.15012896]]
[[-0.55764995]]
[[1.07377277]]
[[0.18390583]]
[[-0.7059611]]
[[-0.40933879]]
[[0.03559468]]
[[0.18390583]]
[[-0.40933879]]
[[-0.26102763]]
[[-0.85427226]]
[[1.22208393]]
[[0.18390583]]
[[2.55688433]]
[[0.03559468]]
[[-0.11271648]]
[[-0.7059611]]

Answer 1

It’s very quiet to do, just need to initialize an array of zeros of the size you want and then go filling in with the values you get.

import numpy as np

Matriz = np.zeros((24,1)) # Inicializa a matriz no formato de 24 linhas por 1 coluna,                               com zeros

for item in range(24):
    Matriz[item][0] = item  # Preenche a matriz com o índice do for

print(Matriz)

print(Matriz[2][0]) # Imprime o valor da 3ª linha

I couldn’t run your code because of dependencies from other places, but the code I did generates the output:

[[ 0.]
 [ 1.]
 [ 2.]
 [ 3.]
 [ 4.]
 [ 5.]
 [ 6.]
 [ 7.]
 [ 8.]
 [ 9.]
 [10.]
 [11.]
 [12.]
 [13.]
 [14.]
 [15.]
 [16.]
 [17.]
 [18.]
 [19.]
 [20.]
 [21.]
 [22.]
 [23.]]
2.0