在 NumPy 中將標量值除以掩碼陣列的每個元素並返回向下取整的值


要將標量值除以掩碼陣列的每個元素並在除法後返回向下取整的值,請在 Python NumPy 中使用 bma.MaskedArray.__floordiv__() 方法。掩碼陣列是標準 numpy.ndarray 和掩碼的組合。掩碼要麼是 nomask(表示關聯陣列的任何值均有效),要麼是布林陣列,用於確定關聯陣列的每個元素的值是否有效。

NumPy 提供了全面的數學函式、隨機數生成器、線性代數例程、傅立葉變換等等。它支援各種硬體和計算平臺,並且與分散式、GPU 和稀疏陣列庫相容良好。

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([[85, 68, 81, 84], [67, 33, 39, 53], [29, 88, 51, 37], [56, 45, 67, 85]])
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, 1, 0], [0, 0, 0, 1], [0, 1, 0, 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)

標量值:

val = 3
print("
The given value to be divided...
",val)

要將標量值除以掩碼陣列的每個元素並在除法後返回向下取整的值,請使用 ma.MaskedArray.__floordiv__() 方法:

print("
Resultant Masked Array...
",maskArr.__floordiv__(val))

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([[85, 68, 81, 84], [67, 33, 39, 53], [29, 88, 51, 37], [56, 45, 67, 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) # The scalar value val = 3 print("
The given value to be divided...
",val) # To divide a scalar value into every element of a masked Array and return the floor value after division, # use the ma.MaskedArray.__floordiv__() method print("
Resultant Masked Array...
",maskArr.__floordiv__(val))

輸出

Array...
[[85 68 81 84]
[67 33 39 53]
[29 88 51 37]
[56 45 67 85]]

Array type...
int64

Array Dimensions...
2

Our Masked Array
[[-- -- 81 84]
[67 33 -- 53]
[29 88 51 --]
[56 -- 67 85]]

Our Masked Array type...
int64

Our Masked Array Dimensions...
2

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

Elements in the Masked Array...
16

The given value to be divided...
3

Resultant Masked Array...
[[-- -- 27 28]
[22 11 -- 17]
[9 29 17 --]
[18 -- 22 28]]

更新於:2022年2月5日

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