In the finite element method, the shape functions i (x) are defined on reference elements
(Figures 1(a) and (b)), and through an isoparametric transformation, they are obtained on any
triangle or convex quadrilateral. Finite element basis functions satisfy three key properties, which
facilitates the exact imposition of linear Dirichlet boundary conditions:
1. Basis functions satisfy linear reproducing conditions (linearly complete) on meshes with
either triangular or quadrilateral elements.
2. Interior nodal basis functions do not contribute at a point p that lies on the boundary of the
domain.
3. The basis functions possess the Kronecker-delta property (cardinal basis): i (x j )=i j .
On meshes with convex n-gons, MAXENT basis functions are a barycentric co-ordinate and they
satisfy all the above properties [11]. Maximum-entropy basis functions meet the first and second
property on convex domains, but for three or more nodes that are collinear on the boundary of the
domain, a weaker Kronecker-delta property is satisfied. Extensive research in meshfree methods
has focused on modifications to MLS (e.g. use of singular weight functions or transformations)
and to other meshfree approximants with the objective of constructing basis functions with the
Kronecker-delta property. The lack of the Kronecker-delta property on the boundary by itself
does not pose any limitation; the first two properties that are indicated above are the critical ones
and they suffice to enable the imposition of essential boundary conditions in MAXENT meshfree
methods as in finite elements [12].