在 NumPy 中沿着轴 1 查找掩码数组中连续的未掩码数据


要查找沿给定轴的掩码数组中连续的未掩码数据,请在 Python NumPy 中使用 **numpy.ma.notmasked_contiguous**。该方法返回数组中未掩码索引的切片(起始和结束索引)列表。如果输入是二维的并且指定了轴,则结果是列表的列表。

轴是执行操作的轴。如果为 None(默认值),则应用于数组的扁平版本,这与 flatnotmasked_contiguous 相同。

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掩盖其中一些无效元素:

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数量:

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

返回一个布尔值,指示数据是否连续:

print("
Check whether the data is contiguous?
",maskArr.iscontiguous())

要查找沿给定轴的掩码数组中连续的未掩码数据,请使用 numpy.ma.notmasked_contiguous:

print("
Result...
",np.ma.notmasked_contiguous(maskArr, axis = 1))

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) # Return a boolean indicating whether the data is contiguous print("
Check whether the data is contiguous?
",maskArr.iscontiguous()) # To find contiguous unmasked data in a masked array along the given axis, use the numpy.ma.notmasked_contiguous in Python Numpy print("
Result...
",np.ma.notmasked_contiguous(maskArr, axis = 1))

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

Check whether the data is contiguous?
True

Result...
[[slice(2, 3, None)], [slice(1, 3, None)], [slice(0, 1, None), slice(2, 3, None)], [slice(0, 1, None),
slice(2, 3, None)]]

更新于:2022年2月4日

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