返回两个掩码一维 NumPy 数组的外积

要返回两个掩码 1D 数组的外积，请在 Python NumPy 中使用 **ma.outer()** 方法。第一个参数是输入向量。如果输入不是一维的，则会被展平。第二个参数是第二个输入向量。如果输入不是一维的，则会被展平。

掩码数组是标准 numpy.ndarray 和掩码的组合。掩码要么是 nomask，表示关联数组的任何值都不无效，要么是布尔值的数组，用于确定关联数组的每个元素的值是否有效。

步骤

首先，导入所需的库 -

import numpy as np

创建数组 1，使用 numpy.array() 方法创建一个包含 int 元素的一维数组 -

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

＃ 创建掩码数组 1 -

arr1 = ma.array(arr1)

掩码数组 1 -

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

显示掩码数组 1 -

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

创建数组 2，使用 numpy.array() 方法创建另一个包含 int 元素的一维数组 -

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

创建掩码数组 2 -

arr2 = ma.array(arr2)

掩码数组 2 -

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

显示掩码数组 2 -

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

要返回两个掩码 1D 数组的外积，请在 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))

输出

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 -- --]]

更新于: 2022-02-22

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