返回 NumPy 中一维数组未掩盖块对应的切片列表
要返回与一维数组未掩盖块对应的切片列表,请使用 Python NumPy 中的 **ma.clump_unmasked()**。“块”定义为数组的连续区域。返回切片列表,每个切片对应数组中一个连续的未掩盖元素区域。
掩码数组是标准 numpy.ndarray 和掩码的组合。掩码要么是 nomask(表示关联数组中没有无效值),要么是布尔数组,它确定关联数组的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型元素的数组:
arr = np.array([65, 68, 81, 93, 33, 39, 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元素标记为无效:
maskArr = ma.masked_array(arr, mask =[1, 1, 0, 1, 0, 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)
返回一个布尔值,指示数据是否连续:
print("
Check whether the data is contiguous?
",maskArr.iscontiguous())要返回与一维数组未掩盖块对应的切片列表,请使用 ma.clump_unmasked()。“块”定义为数组的连续区域:
print("
Result...
",np.ma.clump_unmasked(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, 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])
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 return a list of slices corresponding to the unmasked clumps of a 1-D array, use the ma.clump_unmasked() in Python Numpy
# A "clump" is defined as a contiguous region of the array.
print("
Result...
",np.ma.clump_unmasked(maskArr))输出
Array... [65 68 81 93 33 39 62 45 67] Array type... int64 Array Dimensions... 1 Our Masked Array [-- -- 81 -- 33 39 62 -- 67] Our Masked Array type... int64 Our Masked Array Dimensions... 1 Our Masked Array Shape... (9,) Elements in the Masked Array... 9 Check whether the data is contiguous? True Result... [slice(2, 3, None), slice(4, 7, None), slice(8, 9, None)]
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