PDERIV Derivative of smooth periodic function
Usage: fd=pderiv(f);
fd=pderiv(f,dim);
fd=pderiv(f,dim,difforder);
PDERIV(f) will compute the derivative of f using a using a 4th order
centered finite difference scheme. f must have been obtained by a
regular sampling. If f is a matrix, the derivative along the columns
will be found.
PDERIV(f,dim) will do the same along dimension dim.
PDERIV(f,dim,difforder) uses a centered finite difference scheme of
order difforder instead of the default.
PDERIV(f,dim,Inf) will compute the spectral derivative using a DFT.
PDERIV assumes that f is a regular sampling of a function on the
torus [0,1). The derivative of a function on a general torus [0,T)
can be found by scaling the output by 1/T.
Package: ltfat