在 NumPy 中沿軸 1 重複掩碼陣列的元素


要重複掩碼陣列的元素,請在 NumPy 中使用 **ma.MaskedArray.repeat()** 方法。“**repeats**”引數設定每個元素的重複次數。repeats 將被廣播以適應形狀。“axis”引數是沿其重複值的軸。軸值設定為 1。

該方法返回輸出陣列,其形狀與 a 相同,除了給定的軸。軸是沿其重複值的軸。預設情況下,使用扁平化的輸入陣列,並返回扁平化的輸出陣列。

步驟

首先,匯入所需的庫:

import numpy as np
import numpy.ma as ma

使用 numpy.array() 方法建立一個包含整型元素的陣列:

arr = np.array([[49, 85, 45], [67, 33, 59]])
print("Array...
", arr) print("
Array type...
", arr.dtype)

獲取陣列的維度:

print("Array Dimensions...
",arr.ndim)

建立一個掩碼陣列,並將其中一些標記為無效:

maskArr = ma.masked_array(arr, mask =[[0, 0, 1], [ 0, 1, 0]])
print("
Our Masked Array
", maskArr) print("
Our Masked Array type...
", maskArr.dtype)

獲取掩碼陣列的維度:

print("
Our Masked Array Dimensions...
",maskArr.ndim)

獲取掩碼陣列的形狀:

print("
Our Masked Array Shape...
",maskArr.shape)

獲取掩碼陣列的元素個數:

print("
Elements in the Masked Array...
",maskArr.size)

要重複掩碼陣列的元素,請在 NumPy 中使用 ma.MaskedArray.repeat() 方法。“repeats”引數設定每個元素的重複次數。repeats 將被廣播以適應形狀。“axis”引數是沿其重複值的軸。預設情況下,使用扁平化的輸入陣列,並返回扁平化的輸出陣列。軸值設定為 1:

print("
Result...
",maskArr.repeat(3, axis = 1))

示例

import numpy as np
import numpy.ma as ma

# Create an array with int elements using the numpy.array() method
arr = np.array([[55, 85, 59, 77], [67, 33, 39, 57], [29, 88, 51, 37], [56, 45, 99, 85]])
print("Array...
", arr) print("
Array type...
", arr.dtype) # Get the dimensions of the Array print("
Array Dimensions...
",arr.ndim) # Create a masked array and mask some of them as invalid maskArr = ma.masked_array(arr, mask =[[1, 1, 0, 0], [ 0, 0, 1, 0], [0, 0, 0, 1], [0, 1, 0, 0]]) print("
Our Masked Array
", maskArr) print("
Our Masked Array type...
", maskArr.dtype) # Get the dimensions of the Masked Array print("
Our Masked Array Dimensions...
",maskArr.ndim) # Get the shape of the Masked Array print("
Our Masked Array Shape...
",maskArr.shape) # Get the number of elements of the Masked Array print("
Elements in the Masked Array...
",maskArr.size) # To repeat elements of a masked array, use the ma.MaskedArray.repeat() method in Numpy # The "repeats" parameter sets the number of repetitions for each element. # The repeats is broadcasted to fit the shape. # The "axis" parameter is the axis along which to repeat values. # By default, use the flattened input array, and return a flat output array. # The axis value set to 1 print("
Result...
",maskArr.repeat(3, axis = 1))

輸出

Array...
[[55 85 59 77]
[67 33 39 57]
[29 88 51 37]
[56 45 99 85]]

Array type...
int64

Array Dimensions...
2

Our Masked Array
[[-- -- 59 77]
[67 33 -- 57]
[29 88 51 --]
[56 -- 99 85]]

Our Masked Array type...
int64

Our Masked Array Dimensions...
2

Our Masked Array Shape...
(4, 4)

Elements in the Masked Array...
16

Result...
[[-- -- -- -- -- -- 59 59 59 77 77 77]
[67 67 67 33 33 33 -- -- -- 57 57 57]
[29 29 29 88 88 88 51 51 51 -- -- --]
[56 56 56 -- -- -- 99 99 99 85 85 85]]

更新於:2022年2月4日

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