I want to convert a label numpy array into binary matrix?

Question

I have numpy array:

a = [355, 355, 1005, 7005, 7005, 7005]

I like this to be converted into binary matrix without any loop (if possible using a single line of code) like this:

m = [[1, 1, 0, 0, 0, 0], [0, 0, 1, 0, 0, 0], [0, 0, 0, 1, 1, 1]]

mozway · Accepted Answer · 2022-06-20 08:07:55Z

4

The logic is not fully clear, do you want some kind of one-hot encoding?

a = np.array([355, 355, 1005, 7005, 7005, 7005])

m = (a==np.unique(a,)[:,None]).astype(int)

output:

array([[1, 1, 0, 0, 0, 0],
       [0, 0, 1, 0, 0, 0],
       [0, 0, 0, 1, 1, 1]])

answered Jun 20, 2022 at 8:07

mozway

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2 Comments

I don't know whether the output of an unordered input array meets the requirements of OP, maybe it needs to return_index.

@MechanicPig I don't know the exact logic (thus my question), but yes, the order can be rearranged depending on the use case