Modified Finite Difference Schemes on Uniform Grids for Simulations of the Helmholtz Equation at Any Wave Number

Table 4

Coefficients of the th node for modified and standard central and forward and backward schemes for (23), where the coefficients for standard schemes can be recovered from the real part of the series representations of the modified coefficients.

	Modified coefficient	Standard coefficient
Central
Scheme
Forward
Scheme
Backward
Scheme