fourlap.m

Fourier spectral representation of the Laplacian acting on a 3D data array. Fourier spectral differentiation operators are exact on a given grid when the data array satisfies the Larmor condition on that grid.

Syntax

    L=fourlap(npoints,extents)

Parameters

    npoints -  a three-element vector specifying the number of
               discretization points in each dimension of the
               3D cube of data that the operator will be acting
               on, ordered as [X Y Z].

    extents -  a three-element vector specifying axis extents,
               ordered as [X Y Z].

Outputs

    L - Fourier spectral Laplacian, a sparse matrix designed to act 
        on the vectorization of the 3D data array. The dimensions of
        the data array are assumed to be ordered as [X Y Z].

Notes

Periodic boundary conditions.

See also

fdmat.m, fdvec.m, hydrodynamics.m, fdhess.m, fdkup.m, fourdif.m, fftdiff.m, acomm.m, arnoldi.m, atranspose.m, aux_mat.m, binpack.m, cheap_norm.m, cheb_coeff.m, clean_up.m, dirdiff.m, eigenfields.m, expdrop.m, expmint.m, expmint2.m, frob_chop.m, gaussfun.m, hdot.m, herm_spline.m, jacobianest.m, keep_rank.m, krondelta.m, kronm_new.m, logfactorial.m, lorentzcon.m, lorentzfun.m, md5_hash.m, mprealloc.m, remncomm.m, remtrace.m, rspert.m, rspt_eig.m, snormpdf.m, svd_shrink.m, tikhoind.m, tikhonov.m, trapdiff.m, unit_oper.m, unit_state.m, vvpert.m, Kernel_utilities

Version 2.1, authors: Ilya Kuprov