helpme.py 文件源码

def chivecfn(theta):
    """A version of lnprobfn that returns the simple uncertainty 
    normalized residual instead of the log-posterior, for use with 
    least-squares optimization methods like Levenburg-Marquardt.
    """
    lnp_prior = model.prior_product(theta)
    if not np.isfinite(lnp_prior):
        return -np.infty

    # Generate mean model
    t1 = time.time()
    try:
        spec, phot, x = model.mean_model(theta, obs, sps=sps)
    except(ValueError):
        return -np.infty
    d1 = time.time() - t1

    chispec = chi_spec(spec, obs)
    chiphot = chi_phot(phot, obs)
    return np.concatenate([chispec, chiphot])