Difference between revisions of "Fftdiff.m"
(Normalise sequential blank lines) |
(Update function See also links and function index membership) |
||
| (2 intermediate revisions by the same user not shown) | |||
| Line 1: | Line 1: | ||
| − | {{DISPLAYTITLE:fftdiff.m}} | + | {{DISPLAYTITLE:fftdiff.m}} __NOTOC__ |
Spectral differentiation kernel. Differentiation corresponds to multiplication in the Fourier domain. This function generates the multiplier. | Spectral differentiation kernel. Differentiation corresponds to multiplication in the Fourier domain. This function generates the multiplier. | ||
| Line 6: | Line 6: | ||
kern=fftdiff(order,npoints,dx) | kern=fftdiff(order,npoints,dx) | ||
| − | == | + | ==Parameters== |
order - order of the derivative | order - order of the derivative | ||
| Line 26: | Line 26: | ||
==See also== | ==See also== | ||
| − | [[fdmat.m]], [[fdvec.m]], [[fourlap.m]], [[fourdif.m]] | + | [[fdmat.m]], [[fdvec.m]], [[fourlap.m]], [[fourdif.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]]'' | ''Version 2.1, authors: [[Ilya Kuprov]]'' | ||
Latest revision as of 19:36, 6 June 2026
Spectral differentiation kernel. Differentiation corresponds to multiplication in the Fourier domain. This function generates the multiplier.
Syntax
kern=fftdiff(order,npoints,dx)
Parameters
order - order of the derivative
npoints - number of points in the grid
dx - grid step length
Outputs
kern - a vector that is to be used for accurate
numerical differentiation of periodic real
signals in the following way:
derivative=real(ifft(fft(signal).*kern));
Notes
Periodic boundary conditions.
See also
fdmat.m, fdvec.m, fourlap.m, fourdif.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
