Details of the algorithm are described in . This implementation converts the finite difference scheme to the standard
form and uses the built-in Mathematica
to obtain the solution. Sparse matrices are used. The matrix
and its eigenvalues and the numerical solution vector
can be viewed using the dropdown menu. The table below summarizes the boundary conditions, with
the values at the left and right boundaries,
the length of the domain, and
the solution at the left and right edge of the domain, respectively.
 Y. S. Wong and G. Li, "Exact Finite Difference Schemes for Solving Helmholtz Equations at Any Wavenumber," International Journal of Numerical Analysis and Modeling B
(1), 2010 pp. 91–108.