“…With about 5 or more free parameters, each theoretical spectrum is a single stellar burst defined by metallicity and age, superimposed at a given mass fraction on a spectral component with exponentially decreasing star formation rate characterized by the age of the oldest stars, e-folding time of star formation, and both spectral components could be dust-attenuated. Similarly, 10 5 − 10 6 theoretical spectra are considered in parameter estimation on stellar spectra (e.g., Robitaille et al 2007, who considered a model defined by 14 parameters), and on H II regions (e.g., Morisset 2009, who studied a model defined by 15 parameters). One approach to prepare and manage a non-analytical model is to store all of the precalculated spectra, fixed at both the parameter choice and the parameter resolution.…”