Source code for allensdk.brain_observatory.findlevel

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import numpy as np


def findlevel(inwave, threshold, direction='both'):
    temp = inwave - threshold
    if (direction.find("up") + 1):
        crossings = np.nonzero(np.ediff1d(np.sign(temp), to_begin=0) > 0)
    elif (direction.find("down") + 1):
        crossings = np.nonzero(np.ediff1d(np.sign(temp), to_begin=0) < 0)
    else:
        crossings = np.nonzero(np.ediff1d(np.sign(temp), to_begin=0))

    if len(crossings) == 0 or len(crossings[0]) == 0:
        return None

    return crossings[0][0]