Fftdiff.m

Spectral differentiation kernel.

Syntax

    kern=fftdiff(order,npoints,dx)

Description

Differentiation corresponds to multiplication in the Fourier domain. This function generates the multiplier.

Arguments

      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

Version 2.1, authors: Ilya Kuprov