Figure , Panel B shows the corresponding orthonormal vectors that weigh the basis curves to give curves in Panel A. These basis weightings suggest that the different orthogonal basis functions can be ascribed qualitative physical meaning relative to the underlying distribution. Because it has no zero crossings (blue the first rate-domain coefficient integrates intensity from the entire distribution. Because it has one zero crossing (orange curve), the second parameter is related to the difference between contributions of fast and slow contributions. Third and higher parameters reflect contributions from three and more regions. By invoking increasing numbers of orthogonal basis parameters, the underlying distribution of components is described with increasing precision. This is somewhat analogous to the way increasing the number of Fourier basis functions increases the fineness with which frequencies of an oscillating signal can be localized. When Fourier weightings (not shown) are overtly used to weigh the basis decay curves, they lead to time domain weighting functions shown in Figure Panel D. These functions are not simple and have the disadvantage of not being orthogonal along the time axis. They have advantages, however, for regularization as discussed below.