| # Power law model fitting Returning to the example involving power laws, we ask the question of finding the ‘‘best’’ model of the form given experiments with several input vectors and associated outputs , . Here the variables of our problem are , and the vector . Taking logarithms, we obtain We can write the above linear equations compactly as In practice, the power law model is only an approximate model of the reality. Finding the best fit can be addressed via the optimization problem where , , with -th column given by . See also: Power laws.