Function _debug_rotation

experiments/python/product_quantize.py:202–219

(R)

def _debug_rotation(R):
    D = np.max(R.shape)
    identity = np.identity(D, dtype=np.float32)
    RtR = np.dot(R.T, R)

    R_det = np.linalg.det(RtR)
    print "determinant of R*R: ", R_det
    R_trace = np.trace(RtR)
    print "trace of R*R, trace divided by D: {}, {}".format(R_trace, R_trace / D)
    off_diagonal_abs_mean = np.mean(np.abs(RtR - identity))
    print "mean(abs(off diagonals of R*R)): ", off_diagonal_abs_mean

    if R_det < .999 or R_det > 1.001:
        raise NumericalException("Bad determinant")
    if R_trace < .999 * D or R_trace > 1.001 * D:
        raise NumericalException("Bad trace")
    if off_diagonal_abs_mean > .001:
        raise NumericalException("Bad off-diagonals")


def opq_rotate(X, R):  # so other code need not know what to transpose