mirror of https://github.com/pyodide/pyodide.git
32 lines
949 B
Python
32 lines
949 B
Python
# https://github.com/iskandr/parakeet/blob/master/benchmarks/nd_local_maxima.py
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# setup: import numpy as np ; shape = (3,2,3,2) ; x = np.arange(36, dtype=np.float64).reshape(*shape) # noqa
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# run: local_maxima(x)
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# pythran export local_maxima(float [][][][])
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import numpy as np
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def wrap(pos, offset, bound):
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return (pos + offset) % bound
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def clamp(pos, offset, bound):
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return min(bound - 1, max(0, pos + offset))
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def reflect(pos, offset, bound):
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idx = pos + offset
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return min(2 * (bound - 1) - idx, max(idx, -idx))
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def local_maxima(data, mode=wrap):
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wsize = data.shape
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result = np.ones(data.shape, bool)
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for pos in np.ndindex(data.shape):
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myval = data[pos]
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for offset in np.ndindex(wsize):
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neighbor_idx = tuple(mode(p, o - w // 2, w)
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for (p, o, w) in zip(pos, offset, wsize))
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result[pos] &= (data[neighbor_idx] <= myval)
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return result
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