Difference between revisions of "Fdmat.m"
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D=fdmat(dim,nstenc,order,boundary) | D=fdmat(dim,nstenc,order,boundary) | ||
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dim - dimension of the column vector to be | dim - dimension of the column vector to be | ||
Revision as of 18:48, 5 June 2026
Returns arbitrary-order central finite-difference differentiation matrices (sparse) with unit grid point spacing.
Syntax
D=fdmat(dim,nstenc,order,boundary)
Parameters
dim - dimension of the column vector to be
differentiated
nstenc - number of points in the finite diffe-
rence stencil
order - order of the derivative required
boundary - 'wall' fills the edges with sided
finite difference schemes, 'pbc'
assumes periodic boundaries. The
default is 'pbc'.
Outputs
D - finite difference differentiation matrix
Examples
A three-point second derivative matrix designed to act on a vector with ten elements with periodic boundary conditions is:
>> full(fdmat(10,3,2,'pbc'))
ans =
-2 1 0 0 0 0 0 0 0 1
1 -2 1 0 0 0 0 0 0 0
0 1 -2 1 0 0 0 0 0 0
0 0 1 -2 1 0 0 0 0 0
0 0 0 1 -2 1 0 0 0 0
0 0 0 0 1 -2 1 0 0 0
0 0 0 0 0 1 -2 1 0 0
0 0 0 0 0 0 1 -2 1 0
0 0 0 0 0 0 0 1 -2 1
1 0 0 0 0 0 0 0 1 -2
See also
fdvec.m, fdlap.m, fdhess.m, fdkup.m, fdweights.m, fftdiff.m, fourdif.m, fourlap.m
Version 2.2, authors: Ilya Kuprov
