def dB_nu_dT(nu, T):

    b = B_nu(nu, T)

    x = h * nu / k / T
    f = np.zeros(nu.shape)

    main = x >= 1.e-14
    f[main] = x[main] / T / (1 - np.exp(-x[main])) * b[main]

    small = x < 1e-14
    f[small] = b[small] / T

    return f
dataset/ETHPy150Open hyperion-rt/hyperion/hyperion/util/functions.py/dB_nu_dT/original