Numerical grid generation has now become a fairly common tool for use in the
numerical solution of partial differential equations on arbitrarily shaped regions. This is
especially true in computational fluid dynamics, from whence has come much of the impetus
for the development of this technique, but the procedures are equally applicable to all
physical problems that involve field solutions. Numerically generated grids have provided
the key to removing the problem of boundary shape from finite difference methods, and
these grids also can serve for the construction of finite element meshes. With such grids all
numerical algorithms, finite difference or finite element, are implemented on a square grid in
a rectangular computational region regardless of the shape and configuration of the physical
region. (Finite volume methods are effectively a type of conservative finite difference
method on these grids.)