使用NumPy將無效資料掩蓋並替換為填充值後的返回值


要返回將無效資料掩蓋並替換為填充值後的輸入,請在Python NumPy中使用**numpy.ma.fix_invalid()**方法。掩碼陣列是標準numpy.ndarray和掩碼的組合。掩碼要麼是nomask(表示關聯陣列中沒有無效值),要麼是布林值陣列,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
import numpy.ma as ma

使用numpy.array()方法建立一個包含整數元素的陣列:

arr = np.array([[65, 68, 81], [93, 33, 39], [73, 88, 51], [62, 45, 67]])
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 =[[1, 1, 0], [ 0, 0, 0], [0, 1, 0], [0, 1, 0]])
print("
Our Masked Array
", maskArr) print("
Our Masked Array type...
", maskArr.dtype)

獲取陣列的維度:

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

獲取陣列的形狀:

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

獲取陣列的元素個數:

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

要返回將無效資料掩蓋並替換為填充值後的輸入,請在Python NumPy中使用numpy.ma.fix_invalid()方法

print("
Result...
",np.ma.fix_invalid(arr))

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([[65, 68, 81], [93, 33, 39], [73, 88, 51], [62, 45, 67]])
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], [0, 1, 0], [0, 1, 0]]) print("
Our Masked Array
", maskArr) print("
Our Masked Array type...
", maskArr.dtype) # Get the dimensions of the Array print("
Our Masked Array Dimensions...
",arr.ndim) # Get the shape of the Array print("
Our Masked Array Shape...
",arr.shape) # Get the number of elements of the Array print("
Elements in the Masked Array...
",arr.size) # To return input with invalid data masked and replaced by a fill value, use the numpy.ma.fix_invalid() method in Python Numpy print("
Result...
",np.ma.fix_invalid(arr))

輸出

Array...
[[65 68 81]
[93 33 39]
[73 88 51]
[62 45 67]]

Array type...
int64

Array Dimensions...
2
Our Masked Array
[[-- -- 81]
[93 33 39]
[73 -- 51]
[62 -- 67]]

Our Masked Array type...
int64

Our Masked Array Dimensions...
2

Our Masked Array Shape...
(4, 3)

Elements in the Masked Array...
12

Result...
[[65 68 81]
[93 33 39]
[73 88 51]
[62 45 67]]

更新於:2022年2月4日

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