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]]
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