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)
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