def sigmoid_rampup(current, rampup_length):
    'Exponential rampup from https://arxiv.org/abs/1610.02242'
    if (rampup_length == 0):
        return 1.0
    else:
        current = np.clip(current, 0.0, rampup_length)
        phase = (1.0 - (current / rampup_length))
        w = float(np.exp((((- 2.0) * phase) * phase)))
        return min(w, 0.5)
Exponential rampup from https://arxiv.org/abs/1610.02242
def sigmoid_rampup(current, rampup_length):
    
    if (rampup_length == 0):
        return 1.0
    else:
        current = np.clip(current, 0.0, rampup_length)
        phase = (1.0 - (current / rampup_length))
        w = float(np.exp((((- 2.0) * phase) * phase)))
        return min(w, 0.5)