Class lsst::shapelet::MultiShapeletBasis

class MultiShapeletBasis

A basis formed from a linear combination of shapelet bases that differ only in radius.

A MultiShapeletBasis can have many “components” (shapelet bases with different orders and radii), which are mapped via matrices into one or more “elements”. It’s common for a basis to have only one or two elements, representing a galaxy model that is a linear combination of one or two radial profiles. It’s also common for most components to be zeroth order (Gaussians), as higher- order shapelet terms don’t provide much of an advantage when approximating axisymmetric functions.

MultiShapeletBasis itself provides the interface to define these multi-Gaussian approximations and combine and refine them, and delegates the work of defining them to MultiShapeletFunction (via the makeFunction() method) and the MultiShapeletMatrixBuilder class. MultiShapeletFunction is a more user-friendly and versatile approach, intended for debugging and testing, while the MultiShapletMatrixBuilder approach is intended for performance-critical evaluation of PSF-convolved MultiShapeletBasis objects.