
20 Meshless methods and their numerical properties
are substituted by the trial function
ii
. The important
difference between the NEM and FEM is that the function in the FEM is
approximated within the element and it is discontinuous over the element
boundaries, while the function in the NEM is approximated by the natural
neighbour coordinates that are continuous and differentiable everywhere,
except at the interested node itself. In order to compute the spatial deriv-
atives in the NEM, a generalized and versatile approach was developed
(Braun and Sambridge, 1995) that works with the n dimensions.
NEM presents several advantage ...