CODEWITHSUNDEEP
pythonarraysnumpy
obtmind
obtmind

Reputation: 287

Furthest location in matrix with certain value

Lets say I have a binary matrix, how do I find the (row,col) location of the furthest north, south, east, and west with a value of 1 (or 0).

Can this be easily transferred to finding the same furthest regions with a specific value in non binary matrices?

Upvotes: 0

Views: 96

Answers (1)

Daniel F
Daniel F

Reputation: 14399

You can just look up the indices of any column or row that has a True in it.

NS = np.where(np.any(M, axis=0))[0]
WE = np.where(np.any(M, axis=1))[0]

Take the first and last to get the extents:

N = NS[0]
S = NS[-1]
W = WE[0]
E = WE[-1]

For a non-boolean matrix M you'd need to do some comparison that will output a boolean matrix, like:

NS = np.where(np.any(M > 0, axis=0))[0]
WE = np.where(np.any(M > 0, axis=1))[0]

Upvotes: 1

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