在 NumPy 中沿特定軸連線一系列掩碼陣列


要連線一系列掩碼陣列,請使用 Python NumPy 中的 **ma.concatenate()** 方法。“**axis**”引數用於設定軸。

引數是必須具有相同形狀的陣列,除了對應於軸的維度(預設情況下為第一個維度)之外。軸是沿其連線陣列的軸。預設為 0。該函式返回連線後的陣列,並保留任何掩碼條目。

步驟

首先,匯入所需的庫:

import numpy as np
import numpy.ma as ma

建立陣列 1,一個使用 numpy.arange() 方法建立的包含 int 元素的 3x3 陣列:

arr1 = np.arange(9).reshape((3,3))
print("Array1...
", arr1) print("
Array type...
", arr1.dtype)

建立一個掩碼陣列 1:

arr1 = ma.array(arr1)

掩碼陣列 1:

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

顯示掩碼陣列 1:

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

建立陣列 2,一個使用 numpy.arange() 方法建立的包含 int 元素的 3x3 陣列:

arr2 = np.arange(9).reshape((3,3))
print("
Array2...
", arr2) print("
Array type...
", arr2.dtype)

建立一個掩碼陣列 2:

arr2 = ma.array(arr2)

掩碼陣列 2:

arr2[2, 1] = ma.masked
arr2[2, 2] = ma.masked

顯示掩碼陣列 2:

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

要連線一系列掩碼陣列,請使用 Python NumPy 中的 ma.concatenate() 方法。“axis”引數用於設定軸。

print("
Result of concatenation...
",ma.concatenate([arr1, arr2], axis = 1))

示例

# Python ma.MaskedArray - Concatenate a sequence of masked arrays along specific axis

import numpy as np
import numpy.ma as ma

# Array 1
# Creating a 3x3 array with int elements using the numpy.arange() method
arr1 = np.arange(9).reshape((3,3))
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, 1] = ma.masked arr1[1, 1] = ma.masked # Display Masked Array 1 print("
Masked Array1...
",arr1) # Array 2 # Creating another 3x3 array with int elements using the numpy.arange() method arr2 = np.arange(9).reshape((3,3)) 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[2, 1] = ma.masked arr2[2, 2] = ma.masked # Display Masked Array 2 print("
Masked Array2...
",arr2) # To concatenate a sequence of arrays, use the ma.concatenate() method in Python Numpy print("
Result of concatenation...
",ma.concatenate([arr1, arr2], axis = 1))

輸出

Array1...
[[0 1 2]
[3 4 5]
[6 7 8]]

Array type...
int64

Array Dimensions...
2

Our Array Shape...
(3, 3)

Elements in the Array...
9

Masked Array1...
[[0 -- 2]
[3 -- 5]
[6 7 8]]

Array2...
[[0 1 2]
[3 4 5]
[6 7 8]]

Array type...
int64

Array Dimensions...
2

Our Array Shape...
(3, 3)

Elements in the Array...
9

Masked Array2...
[[0 1 2]
[3 4 5]
[6 -- --]]

Result of concatenation...
[[0 -- 2 0 1 2]
[3 -- 5 3 4 5]
[6 7 8 6 -- --]]

更新於:2022年2月3日

506 次瀏覽

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