1. A method of determining a number of profiles for a training data set to be used in training a machine learning system to generate simulated spectral information from modeled profile parameters, the method comprising: generating a first characterizing metric for a training data set with a first number of profiles; expanding the first training data set to include a second number of profiles greater than the first number of profiles; generating a second characterizing metric for the expanded training data set; and defining the number of profiles for training the machine learning system to include the first number of profiles in response to the first and second characterizing metrics converging within a predetermined threshold.