在 NumPy 中使用标量值添加掩码数组的每个元素

要将掩码数组的每个元素与标量值 val 相加，请使用 **ma.MaskedArray.__add__()** 方法。返回一个数组，该数组的值为每个元素加上 val。掩码数组是标准 numpy.ndarray 和掩码的组合。掩码要么是 nomask，表示关联数组的任何值均无效，要么是布尔值数组，用于确定关联数组的每个元素的值是否有效。

NumPy 提供了全面的数学函数、随机数生成器、线性代数例程、傅里叶变换等等。它支持各种硬件和计算平台，并且与分布式、GPU 和稀疏数组库配合良好。

步骤

首先，导入所需的库 -

import numpy as np
import numpy.ma as ma

使用 numpy.array() 方法创建具有整数元素的数组 -

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)

获取数组的维度 -

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

创建一个掩码数组，并将其中一些掩码为无效 -

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)

获取掩码数组的维度 -

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

获取掩码数组的形状 -

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

获取掩码数组的元素数量 -

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

要添加的标量 -

val = 25
print("
The given value to be added with the array elements...
",val)

要将掩码数组的每个元素与标量值 val 相加，请使用 ma.MaskedArray.__add__() 方法。返回一个数组，该数组的值为每个元素加上 val -

print("
Resultant Masked Array...
",maskArr.__add__(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 to be added
val = 25
print("
The given value to be added with the array elements...
",val)

# To add each and every element of a masked array with a scalar value val, use the ma.MaskedArray.__add__() method
# Returns the array with the value val added to every element
print("
Resultant Masked Array...
",maskArr.__add__(val))

输出

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 added with the array elements...
25

Resultant Masked Array...
[[-- -- 106 109]
[92 58 -- 78]
[54 113 76 --]
[81 -- 92 110]]

AmitDiwan

更新于: 2022年2月5日

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