def house( self, index ):
        v = Vec( Table([0]*index).concat(self[index:]) ).normalize()
        t = v[index]
        sigma = 1.0 - t**2
        if sigma != 0.0:
            t = v[index] = t<=0 and t-1.0 or -sigma / (t + 1.0)
            v /= t
        return v, 2.0 * t**2 / (sigma + t**2)
Compute a Householder vector which zeroes all but the index element after a reflection
dataset/ETHPy150Open sunlightlabs/clearspending/completeness/statlib/matfunc.py/Vec.house