返回NumPy中掩码数组的数据区域和掩码区域的地址


要返回掩码数组的数据区域和掩码区域的地址,请在Python NumPy中使用**ma.MaskedArray.ids()**方法。

掩码数组是标准numpy.ndarray和掩码的组合。掩码或者是nomask(表示关联数组中没有无效值),或者是一个布尔值数组,它决定关联数组的每个元素的值是否有效。

NumPy提供全面的数学函数、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和稀疏数组库兼容良好。

步骤

首先,导入所需的库:

import numpy as np
import numpy.ma as ma

使用numpy.array()方法创建一个包含整数元素的数组:

arr = np.array([[65, 68, 81], [93, 33, 39], [73, 88, 51], [62, 45, 67]])
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,并将其中一些标记为无效:

maskArr = ma.masked_array(arr, mask =[[1, 1, 0], [ 1, 0, 0], [0, 1, 0], [0, 1, 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个数:

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

要返回掩码数组的数据区域和掩码区域的地址,请使用ma.MaskedArray.ids()方法:

print("
Resultant Array...
",maskArr.ids())

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], [ 1, 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 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) # To return the addresses of the data and mask areas of a masked array, use the ma.MaskedArray.ids() method print("
Resultant Array...
",maskArr.ids())

输出

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

Array type...
int64

Array Dimensions...
2

Our Masked Array
[[-- -- 81]
[-- 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

Resultant Array...
(93885016023728, 93885016183488)

更新于:2022年2月17日

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