在 NumPy 中查找掩码数组中连续的未掩码数据

要查找掩码数组中连续的未掩码数据，请使用 Python NumPy 中的 numpy.ma.flatnotmasked_contiguous。slice_list 参数是有序的切片对象序列（开始索引、结束索引）。

掩码数组是标准 numpy.ndarray 和掩码的组合。掩码为 nomask，表示关联数组中没有无效值，或者为布尔数组，该数组确定关联数组中每个元素的值是否有效。

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掩码为无效 -

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数 -

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

返回一个布尔值，表示数据是否连续 -

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

要查找掩码数组中连续的未掩码数据，请使用 numpy.ma.flatnotmasked_contiguous -

print("
Result...
",np.ma.flatnotmasked_contiguous(maskArr))

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, use the numpy.ma.flatnotmasked_contiguous in Python Numpy
print("
Result...
",np.ma.flatnotmasked_contiguous(maskArr))

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(4, 7, None), slice(8, 10, None), slice(11, 12, None)]

AmitDiwan

更新于： 04-Feb-2022

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