NumPy中沿軸1約簡多維陣列


要約簡多維陣列,請使用Python NumPy中的**np.ufunc.reduce()**方法。這裡,我們使用**add.reduce()**將其約簡為元素的加法。軸使用“axis”引數設定。沿其執行約簡的軸。

**numpy.ufunc**具有逐元素操作整個陣列的函式。ufunc是用C語言(為了速度)編寫的,並與NumPy的ufunc工具連結到Python。

通用函式(簡稱ufunc)是在逐元素基礎上操作ndarray的函式,支援陣列廣播、型別轉換以及其他一些標準特性。

也就是說,ufunc是對函式的“向量化”包裝器,該函式採用固定數量的特定輸入併產生固定數量的特定輸出。

步驟

首先,匯入所需的庫:

import numpy as np

建立一個多維陣列:

arr = np.arange(27).reshape((3,3,3))

顯示陣列:

print("Array...
", arr)

獲取陣列的型別:

print("
Our Array type...
", arr.dtype)

獲取陣列的維度:

print("
Our Array Dimensions...
",arr.ndim)

要約簡多維陣列,請使用Python NumPy中的np.ufunc.reduce()方法。這裡,我們使用multiply.reduce()將其約簡為元素的乘法。軸使用“axis”引數設定。沿其執行約簡的軸。

print("
Result (multiplication)...
",np.multiply.reduce(arr, axis = 1))

要約簡多維陣列,請使用Python NumPy中的np.ufunc.reduce()方法。這裡,我們使用add.reduce()將其約簡為元素的加法。軸使用“axis”引數設定。沿其執行約簡的軸:

print("
Result (addition)...
",np.add.reduce(arr, axis = 1))

示例

import numpy as np

# The numpy.ufunc has functions that operate element by element on whole arrays.
# ufuncs are written in C (for speed) and linked into Python with NumPy’s ufunc facility

# Create a multi-dimensional array
arr = np.arange(27).reshape((3,3,3))

# Display the array
print("Array...
", arr) # Get the type of the array print("
Our Array type...
", arr.dtype) # Get the dimensions of the Array print("
Our Array Dimensions...
",arr.ndim) # To reduce a multi-dimensional array, use the np.ufunc.reduce() method in Python Numpy # Here, we have used multiply.reduce() to reduce it to the multiplication of elements elements # The axis is set using the "axis" parameter # Axis or axes along which a reduction is performed print("
Result (multiplication)...
",np.multiply.reduce(arr, axis = 1)) # To reduce a multi-dimensional array, use the np.ufunc.reduce() method in Python Numpy # Here, we have used add.reduce() to reduce it to the addition of elements # The axis is set using the "axis" parameter # Axis or axes along which a reduction is performed print("
Result (addition)...
",np.add.reduce(arr, axis = 1))

輸出

Array...
[[[ 0 1 2]
[ 3 4 5]
[ 6 7 8]]

[[ 9 10 11]
[12 13 14]
[15 16 17]]

[[18 19 20]
[21 22 23]
[24 25 26]]]

Our Array type...
int64

Our Array Dimensions...
3

Result (multiplication)...
[[ 0 28 80]
[ 1620 2080 2618]
[ 9072 10450 11960]]

Result (addition)...
[[ 9 12 15]
[36 39 42]
[63 66 69]]

更新於:2022年2月7日

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