Python中数组矩阵的翻转（翻转180度，向左翻转90度，向右翻转90度）

Python中数组矩阵的翻转（翻转180度，向左翻转90度，向右翻转90度）

转载请表明原处：https://blog.csdn.net/kane7csdn/article/details/83928848

---

先定义数组：

a = np.array(([1, 2, 3], [4, 5, 6], [7, 8, 9]))
a4d = np.array(([1, 2, 3, 4], [2, 3, 4, 5], [3, 4, 5, 6], [4, 5, 6, 7]))
b = np.array(([1, 2, 3], [4, 5, 6]))

# [[1 2 3]
#  [4 5 6]
#  [7 8 9]]

# [[1 2 3 4]
#  [2 3 4 5]
#  [3 4 5 6]
#  [4 5 6 7]]

# [[1 2 3]
#  [4 5 6]]

---

翻转180度：

def flip180(arr):
    new_arr = arr.reshape(arr.size)
    new_arr = new_arr[::-1]
    new_arr = new_arr.reshape(arr.shape)
    return new_arr

print(flip180(a))
# [[9 8 7]
#  [6 5 4]
#  [3 2 1]]
print(flip180(a4d))
# [[7 6 5 4]
#  [6 5 4 3]
#  [5 4 3 2]
#  [4 3 2 1]]
print(flip180(b))
# [[6 5 4]
#  [3 2 1]]

---

向左翻转90度：

def flip90_left(arr):
    new_arr = np.transpose(arr)
    new_arr = new_arr[::-1]
    return new_arr

print(flip90_left(a))
# [[3 6 9]
#  [2 5 8]
#  [1 4 7]]
print(flip90_left(a4d))
# [[4 5 6 7]
#  [3 4 5 6]
#  [2 3 4 5]
#  [1 2 3 4]]
print(flip90_left(b))
# [[3 6]
#  [2 5]
#  [1 4]]

---

向右翻转90度：

def flip90_right(arr):
    new_arr = arr.reshape(arr.size)
    new_arr = new_arr[::-1]
    new_arr = new_arr.reshape(arr.shape)
    new_arr = np.transpose(new_arr)[::-1]
    return new_arr

print(flip90_right(a))
# [[7 4 1]
#  [8 5 2]
#  [9 6 3]]
print(flip90_right(a4d))
# [[4 3 2 1]
#  [5 4 3 2]
#  [6 5 4 3]
#  [7 6 5 4]]
print(flip90_right(b))
# [[4 1]
#  [5 2]
#  [6 3]]