在NumPy中返回一個包含相同資料但具有新形狀的掩碼陣列
要返回一個包含相同資料但具有新形狀的掩碼陣列,請在NumPy中使用 **ma.MaskedArray.reshape()** 方法。賦予陣列新的形狀而無需更改其資料。新形狀應與原始形狀相容。如果提供的是整數,則結果將是一個長度為該整數的一維陣列。
順序決定了陣列資料是否應按C語言(行主序)或FORTRAN(列主序)順序檢視。返回一個包含相同資料但具有新形狀的掩碼陣列。結果是對原始陣列的檢視;如果無法實現此目的,則會引發ValueError。
步驟
首先,匯入所需的庫:
import numpy as np import numpy.ma as ma
使用numpy.array()方法建立一個包含整數元素的陣列:
arr = np.array([[49, 85, 45], [67, 33, 59]])
print("Array...
", arr)
print("
Array type...
", arr.dtype)獲取陣列的維度:
print("Array Dimensions...
",arr.ndim)
建立一個掩碼陣列並掩蓋其中一些無效元素:
maskArr = ma.masked_array(arr, mask =[[0, 0, 1], [ 0, 1, 0]])
print("
Our Masked Array
", maskArr)
print("
Our Masked Array type...
", maskArr.dtype)獲取掩碼陣列的維度:
print("
Our Masked Array Dimensions...
",maskArr.ndim)
獲取掩碼陣列的形狀:
print("
Our Masked Array Shape...
",maskArr.shape)獲取掩碼陣列的元素數量:
print("
Elements in the Masked Array...
",maskArr.size)
要返回一個包含相同資料但具有新形狀的掩碼陣列,請使用ma.MaskedArray.reshape()方法。賦予陣列新的形狀而無需更改其資料。掩碼陣列的新形狀設定為6x1作為引數。新形狀應與原始形狀相容。如果提供的是整數,則結果將是一個長度為該整數的一維陣列:
print("
Result...
",maskArr.reshape((6,1)))示例
# Python ma.MaskedArray - Return a masked array containing the same data but with a new shape
import numpy as np
import numpy.ma as ma
# Create an array with int elements using the numpy.array() method
arr = np.array([[78, 85, 51], [56, 33, 97]])
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
# The masked array is 1x6
maskArr = ma.masked_array(arr, mask =[[0, 1, 0, 0, 0, 1]])
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 a masked array containing the same data, but with a new shape, use the ma.MaskedArray.reshape() method in Numpy
# Give a new shape to the array without changing its data
# The new shape of the masked array is set to 6x1 as a parameter
# The new shape should be compatible with the original shape.
# If an integer is supplied, then the result will be a 1-D array of that length
print("
Result...
",maskArr.reshape((6,1)))輸出
Array... [[78 85 51] [56 33 97]] Array type... int64 Array Dimensions... 2 Our Masked Array [[78 -- 51] [56 33 --]] Our Masked Array type... int64 Our Masked Array Dimensions... 2 Our Masked Array Shape... (2, 3) Elements in the Masked Array... 6 Result... [[78] [--] [51] [56] [33] [--]]
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