numpy.atleast_3d

numpy.atleast_3d(*arys)      [source]

将输入查看为至少具有三个维度的数组。

例子

1）一维数组转三维

import numpy as np

arr1d = np.array([1, 2, 3])
arr3d = np.atleast_3d(arr1d)

print("原数组:")
print(arr1d)
print("转换后的数组:")
print(arr3d)
print("转换后的形状:", arr3d.shape)

2）二维数组转三维

import numpy as np

arr2d = np.array([[1, 2, 3], [4, 5, 6]])
arr3d = np.atleast_3d(arr2d)

print("原数组:")
print(arr2d)
print("转换后的数组:")
print(arr3d)
print("转换后的形状:", arr3d.shape)

3）三维数组保持不变

import numpy as np

arr3d = np.array([[[1, 2, 3], [4, 5, 6]]])
arr3d_converted = np.atleast_3d(arr3d)

print("原数组:")
print(arr3d)
print("转换后的数组:")
print(arr3d_converted)
print("转换后的形状:", arr3d_converted.shape)

4）多个数组输入

import numpy as np

arr1d = np.array([1, 2, 3])
arr2d = np.array([[4, 5, 6]])
arr3d = np.array([[[7, 8, 9]]])

results = np.atleast_3d(arr1d, arr2d, arr3d)

for i, res in enumerate(results, 1):
    print(f"数组 {i}:")
    print(res)
    print("形状:", res.shape)
    print()

5）使用示例

import numpy as np

# 将标量转换为三维数组
result1 = np.atleast_3d(3.0)
print(result1)
# 输出: array([[[3.]]])

x = np.arange(12.0).reshape(4, 3)
# 检查数组的 base 属性（x 是 reshape 的，所以它的 base 属性没有改变）
is_base_same = np.atleast_3d(x).base is x.base
print(is_base_same)
# 输出: True

# 将多个不同形状的数组转换为三维数组，并打印其形状
arrays = [np.atleast_3d([1, 2]), np.atleast_3d([[1, 2]]), np.atleast_3d([[[1, 2]]])]
for arr in arrays:
    print(arr, arr.shape)