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марат
Asked:2021-12-31 15:24:45 +0000 UTC2021-12-31 15:24:45 +0000 UTC

如何使用 delta 创建数据数组？

  • 772

有一个最终数组arr，其中 3 个数组的长度始终相等

如何创建一个包含数字之间差异的数组？

a = [3, 1, 5, 7, 6, 7, 8, 10, 3, 3]例如，如果现在

那么最后arr[0]应该是[-2,4,2,-1,1,1,2,-7,0]

也许numpy有一些简单的方法可以用一行或其他一些原始方式来完成？可能有很多数据，计算速度非常重要。

import numpy as np
......
 
a = [3, 1, 5, 7, 6, 7, 8, 10, 3, 3]
b = [11, 15, 17, 86, 11, 67, 31, 56, 3, 11]
c = [12.1, 98.2, 31.6, 24.7, 12.1, 34.1, 1.8, 65.1, 22.9, 31.6]
 
arr = np.array([a, b, c])
 
 
arr_delta = arr ?
python

3 个回答

  1. Best Answer

    也许你需要这个？：

    import numpy as np

a = [3, 1, 5, 7, 6, 7, 8, 10, 3, 3]

print(np.diff(np.array(a)))

    [-2 4 2 -1 1 1 2 -7 0]

    更新

    import numpy as np

a = [3, 1, 5, 7, 6, 7, 8, 10, 3, 3]
b = [11, 15, 17, 86, 11, 67, 31, 56, 3, 11]
c = [12.1, 98.2, 31.6, 24.7, 12.1, 34.1, 1.8, 65.1, 22.9, 31.6]


arr_delta = [np.diff(np.array(x)).tolist() for x in (a, b, c)]
print(arr_delta)

    我们得到：

    [[-2, 4, 2, -1, 1, 1, 2, -7, 0], [4, 2, 69, -75, 56, -36, 25, -53, 8], [86.10000000000001, -66.6, -6.900000000000002, -12.6, 22.0, -32.300000000000004, 63.3, -42.199999999999996, 8.700000000000003]]

    因此，arr_delta[0] 将是：

    [-2, 4, 2, -1, 1, 1, 2, -7, 0]

    或者，甚至更短：

    arr = np.array([a, b, c])
arr_delta = [np.diff(x).tolist() for x in arr]
print(arr_delta)

    但在这种情况下，请注意类型转换。

    • 5 
  2. import numpy as np

a = [3, 1, 5, 7, 6, 7, 8, 10, 3, 3]
b = [11, 15, 17, 86, 11, 67, 31, 56, 3, 11]
c = [12.1, 98.2, 31.6, 24.7, 12.1, 34.1, 1.8, 65.1, 22.9, 31.6]

arr = np.array([a, b, c])
res = np.array(
  [arr[0][:-1]-arr[0][1:],
  arr[1][:-1]-arr[1][1:], 
  arr[2][:-1]-arr[2][1:]]
)
    
[[  2.   -4.   -2.    1.   -1.   -1.   -2.    7.    0. ]
 [ -4.   -2.  -69.   75.  -56.   36.  -25.   53.   -8. ]
 [-86.1  66.6   6.9  12.6 -22.   32.3 -63.3  42.2  -8.7]]
    • 1

  3. numpy.diff考虑需要什么（称为最终差异）。传递一个参数axis以指定沿哪个轴计算差异：

    import numpy as np

a = [3, 1, 5, 7, 6, 7, 8, 10, 3, 3]
b = [11, 15, 17, 86, 11, 67, 31, 56, 3, 11]
c = [12.1, 98.2, 31.6, 24.7, 12.1, 34.1, 1.8, 65.1, 22.9, 31.6]
 
arr = np.array([a, b, c])
 
arr_delta = np.diff(arr, axis=1)

print(arr_delta)

    [[ -2.    4.    2.   -1.    1.    1.    2.   -7.    0. ]
 [  4.    2.   69.  -75.   56.  -36.   25.  -53.    8. ]
 [ 86.1 -66.6  -6.9 -12.6  22.  -32.3  63.3 -42.2   8.7]]
    • 1

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