def agdrat_point(anps, tca, pcemic_1_iel, pcemic_2_iel, pcemic_3_iel):
    """Point implementation of `Agdrat.f`.

    Calculate the C/<iel> ratio of new material that is the result of
    decomposition into "box B".

    Parameters:
        anps: <iel> (N or P) in the decomposing stock
        tca: total C in the decomposing stock
        pcemic_1_iel: maximum C/<iel> of new SOM1
        pcemic_2_iel: minimum C/<iel> of new SOM1
        pcemic_3_iel: minimum <iel> content of decomposing material that gives
            minimum C/<iel> of new material

    Returns:
        agdrat, the C/<iel> ratio of new material

    """
    cemicb = (pcemic_2_iel - pcemic_1_iel) / pcemic_3_iel
    if ((tca * 2.5) <= 0.0000000001):
        econt = 0
    else:
        econt = anps / (tca * 2.5)
    if econt > pcemic_3_iel:
        agdrat = pcemic_2_iel
    else:
        agdrat = pcemic_1_iel + econt * cemicb
    return agdrat