Array Dua Dimensi

Pengantar Python untuk Keuangan

Adina Howe

Instructor

Array dua dimensi

import numpy as np

months = [1, 2, 3]
prices = [238.11, 237.81, 238.91]

cpi_array = np.array([months, prices])

print(cpi_array)

[[   1.      2.      3.  ]
 [ 238.11  237.81  238.91]]

print(cpi_array)

[[   1.      2.      3.  ]
 [ 238.11  237.81  238.91]]

.shape memberikan dimensi array

print(cpi_array.shape)

(2, 3)

.size memberikan jumlah total elemen dalam array

print(cpi_array.size)

import numpy as np

prices = [238.11, 237.81, 238.91]
prices_array = np.array(prices)

np.mean() menghitung rata-rata dari suatu input

print(np.mean(prices_array))

238.27666666666667

np.std() menghitung simpangan baku dari suatu input

print(np.std(prices_array))

0.46427960923946671

numpy.arange() membuat array dengan awal, akhir, langkah

import numpy as np

months = np.arange(1, 13)

print(months)

[ 1  2  3  4  5  6  7  8  9 10 11 12]

months_odd = np.arange(1, 13, 2)

print(months_odd)

[ 1  3  5  7  9 11]

numpy.transpose() menukar baris dan kolom dari suatu array numpy

print(cpi_array)

[[   1.      2.      3.  ]
 [ 238.11  237.81  238.91]]

cpi_transposed = np.transpose(cpi_array)

print(cpi_transposed)

[[   1.    238.11]
 [   2.    237.81]
 [   3.    238.91]]

print(cpi_array)

[[   1.      2.      3.  ]
 [ 238.11  237.81  238.91]]

# indeks baris 1, indeks kolom 2 
cpi_array[1, 2]

238.91

# semua baris, kolom ketiga
print(cpi_array[:, 2])

[   3.    238.91]

Pengantar Python untuk Keuangan