I'm pretty new to numpy arrays, and was not able to find a good explanation / example for my issue. I saw things like take() or take_along_axis() but I didn't understood what was going on...

I have this 2D numpy, which may contain N sub-arrays, of each 5 values (h, s, i, x, y):

    values = np.array([
                    [1,2,3,4,5],
                    [1,22,33,44,55],
                    [1,22,333,444,555],
                    [1,22,333,4444,5555],
                    [1,222,33,44,55],
                    [1,222,330,440,550],
                    [10,20,30,40,50],
                    [100,200,300,400,500],
                   ])

As you can see, values can be repeated for a same index. I want to regroup sub-arrays, by indexes values, such as:

1
    2
        3
            4
            5
    22
        33
            44
            55
        333
            444
            555
            4444
            5555
    222
        33
            44
            55
        330
            440
            550
10
    20
        30
            40
            50
100
    200
        300
            400
            500

The goal is to obtain a regular array like:

array = [1, 2, 3, 4 , 5, 22, 33, 44, 55, 333, 444, 555, 4444, 5555, 222, 33, 44, 55, 330, 440, 550, 10, 20, 30, 40, 50, 100, 200, 300, 400, 500]            

Thank you very much for your support.

CodePudding user response：

you can use flatten method list(values.flatten())

CodePudding user response：

Thank you for your answer However, the flatten method wont group indexes by same values. It just reshapes as 1D array.