def transient_calc(tup1, tup2):
    """
    tup1 and tup2 should be tuples of broadcastable form (R, T, A)
    tup1 is ground and tup2 is excited state spectra
    returns dR/R, dT/T, and dA spectra.
    """
    dRR = (tup2[0] - tup1[0]) / tup1[0]
    dTT = (tup2[1] - tup1[1]) / tup1[1]
    dA = tup2[2] - tup1[2]
    return dRR, dTT, dA