返回兩個掩碼一維 NumPy 陣列的外積

要返回兩個掩碼 1D 陣列的外積，請在 Python NumPy 中使用 **ma.outer()** 方法。第一個引數是輸入向量。如果輸入不是一維的，則會被展平。第二個引數是第二個輸入向量。如果輸入不是一維的，則會被展平。

掩碼陣列是標準 numpy.ndarray 和掩碼的組合。掩碼要麼是 nomask，表示關聯陣列的任何值都不無效，要麼是布林值的陣列，用於確定關聯陣列的每個元素的值是否有效。

步驟

首先，匯入所需的庫 -

import numpy as np

建立陣列 1，使用 numpy.array() 方法建立一個包含 int 元素的一維陣列 -

arr1 = np.array([5, 10, 15, 20, 25])
print("Array1...
", arr1)
print("
Array type...
", arr1.dtype)

＃ 建立掩碼陣列 1 -

arr1 = ma.array(arr1)

掩碼陣列 1 -

arr1[0] = ma.masked
arr1[1] = ma.masked

顯示掩碼陣列 1 -

print("
Masked Array1...
",arr1)

建立陣列 2，使用 numpy.array() 方法建立另一個包含 int 元素的一維陣列 -

arr2 = np.array([7, 14, 21, 28, 35])
print("
Array2...
", arr2)
print("
Array type...
", arr2.dtype)

建立掩碼陣列 2 -

arr2 = ma.array(arr2)

掩碼陣列 2 -

arr2[3] = ma.masked
arr2[4] = ma.masked

顯示掩碼陣列 2 -

print("
Masked Array2...
",arr2)

要返回兩個掩碼 1D 陣列的外積，請在 Python NumPy 中使用 ma.outer() 方法 -

print("
Result of outer product...
",np.ma.outer(arr1, arr2))

示例

import numpy as np
import numpy.ma as ma

# Array 1
# Creating a 1D array with int elements using the numpy.array() method
arr1 = np.array([5, 10, 15, 20, 25])
print("Array1...
", arr1)
print("
Array type...
", arr1.dtype)

# Get the dimensions of the Array
print("
Array Dimensions...
",arr1.ndim)

# Get the shape of the Array
print("
Our Array Shape...
",arr1.shape)

# Get the number of elements of the Array
print("
Elements in the Array...
",arr1.size)

# Create a masked array
arr1 = ma.array(arr1)

# Mask Array1
arr1[0] = ma.masked
arr1[1] = ma.masked

# Display Masked Array 1
print("
Masked Array1...
",arr1)

# Array 2
# Creating another 1D array with int elements using the numpy.array() method
arr2 = np.array([7, 14, 21, 28, 35])
print("
Array2...
", arr2)
print("
Array type...
", arr2.dtype)

# Get the dimensions of the Array
print("
Array Dimensions...
",arr2.ndim)

# Get the shape of the Array
print("
Our Array Shape...
",arr2.shape)

# Get the number of elements of the Array
print("
Elements in the Array...
",arr2.size)

# Create a masked array
arr2 = ma.array(arr2)

# Mask Array2
arr2[3] = ma.masked
arr2[4] = ma.masked

# Display Masked Array 2
print("
Masked Array2...
",arr2)

# To return the outer product of two masked arrays, use the ma.outer() method in Python Numpy
print("
Result of outer product...
",np.ma.outer(arr1, arr2))

輸出

Array1...
[ 5 10 15 20 25]

Array type...
int64

Array Dimensions...
1

Our Array Shape...
(5,)

Elements in the Array...
5

Masked Array1...
[-- -- 15 20 25]

Array2...
[ 7 14 21 28 35]

Array type...
int64

Array Dimensions...
1

Our Array Shape...
(5,)

Elements in the Array...
5

Masked Array2...
[7 14 21 -- --]

Result of outer product...
[[-- -- -- -- --]
[-- -- -- -- --]
[105 210 315 -- --]
[140 280 420 -- --]
[175 350 525 -- --]]

AmitDiwan

更新於: 2022-02-22

109 次檢視

開啟你的 職業生涯

透過完成課程獲得認證

開始學習