Non-compact stencil

In numerical methods, particularly when dealing with finite difference methods or grid-based simulations, the term "stencil" refers to a template used to specify how a point in a discrete domain is influenced by its neighboring points. The stencil indicates which neighboring points are taken into account when calculating the value at a specific grid point. A **non-compact stencil** is a type of stencil that includes a relatively large number of neighboring points, often extending several grid points away from the center point of interest.