比較兩個包含NaN值的陣列,並使用Numpy返回逐元素最小值
要比較兩個包含一些NaN值的陣列並返回逐元素最小值,請在Python Numpy中使用**numpy.minimum()** 方法。(原文錯誤地使用了maximum())
如果其中一個被比較的元素是NaN,則返回該元素。
如果兩個元素都是NaN,則返回第一個。
後一種區別對於複數NaN很重要,複數NaN定義為實部或虛部至少有一個是NaN。
最終結果是NaN會被傳播。
返回x1和x2的逐元素最小值。如果x1和x2都是標量,則這是一個標量。
比較兩個陣列並返回一個新陣列,該陣列包含逐元素最小值。如果其中一個被比較的元素是NaN,則返回該元素。如果兩個元素都是NaN,則返回第一個。後一種區別對於複數NaN很重要,複數NaN定義為實部或虛部至少有一個是NaN。最終結果是NaN會被傳播。
步驟
首先,匯入所需的庫:
import numpy as np
使用array()方法建立兩個二維numpy陣列。我們插入了一些包含nan值的元素:
arr1 = np.array([[6, np.nan, np.nan],[25, 11, 0]]) arr2 = np.array([[8, 12, np.nan],[22, 0, 26]])
顯示陣列:
print("Array 1...
", arr1) print("
Array 2...
", arr2)
獲取陣列的型別:
print("
Our Array 1 type...
", arr1.dtype) print("
Our Array 2 type...
", arr2.dtype)
獲取陣列的維度:
print("
Our Array 1 Dimensions...
",arr1.ndim) print("
Our Array 2 Dimensions...
",arr2.ndim)
獲取陣列的形狀:
print("
Our Array 1 Shape...
",arr1.shape) print("
Our Array 2 Shape...
",arr2.shape)
要比較兩個包含NaN值的陣列並返回逐元素最小值,請使用numpy.minimum()方法:
print("
Result (minimum)...
",np.minimum(arr1, arr2))
示例
import numpy as np # Creating two 2D numpy array using the array() method # We have inserted elements with some nan values arr1 = np.array([[6, np.nan, np.nan], [25, 11, 0]]) arr2 = np.array([[8, 12, np.nan],[22, 0, 26]]) # Display the arrays print("Array 1...
", arr1) print("
Array 2...
", arr2) # Get the type of the arrays print("
Our Array 1 type...
", arr1.dtype) print("
Our Array 2 type...
", arr2.dtype) # Get the dimensions of the Arrays print("
Our Array 1 Dimensions...
",arr1.ndim) print("
Our Array 2 Dimensions...
",arr2.ndim) # Get the shape of the Arrays print("
Our Array 1 Shape...
",arr1.shape) print("
Our Array 2 Shape...
",arr2.shape) # To compare two arrays with some NaN values and return the elementwise minimum, use the numpy.maximum() method in Python Numpy # If one of the elements being compared is a NaN, then that element is returned. # If both elements are NaNs then the first is returned. # The latter distinction is important for complex NaNs, which are defined as at least one of the real or imaginary parts being a NaN. # The net effect is that NaNs are propagated. print("
Result (minimum)...
",np.minimum(arr1, arr2))
輸出
Array 1... [[ 6. nan nan] [25. 11. 0.]] Array 2... [[ 8. 12. nan] [22. 0. 26.]] Our Array 1 type... float64 Our Array 2 type... float64 Our Array 1 Dimensions... 2 Our Array 2 Dimensions... 2 Our Array 1 Shape... (2, 3) Our Array 2 Shape... (2, 3) Result (minimum)... [[ 6. nan nan] [22. 0. 0.]]
廣告