Difference between revisions of "Fdlap.m"
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Returns a finite-difference representation of the Laplacian for an array with a user-specified finite difference stencil size. The resulting operator is a sparse matrix designed to act on the vectorisation of the array. The dimensions of the array are assumed to be ordered as [X Y Z]. | Returns a finite-difference representation of the Laplacian for an array with a user-specified finite difference stencil size. The resulting operator is a sparse matrix designed to act on the vectorisation of the array. The dimensions of the array are assumed to be ordered as [X Y Z]. | ||
==Syntax== | ==Syntax== | ||
| − | L=fdlap( | + | L=fdlap(npoints,extents,nstenc) |
==Arguments== | ==Arguments== | ||
| − | dims - a one-element, two-element, or three-element | + | dims - a one-element, two-element, or three-element |
vector specifying the number of discretisation | vector specifying the number of discretisation | ||
points in each dimension of the 1D, 2D, or 3D | points in each dimension of the 1D, 2D, or 3D | ||
| Line 25: | Line 24: | ||
==Outputs== | ==Outputs== | ||
| − | L - a sparse matrix designed to act on the vectori- | + | L - a sparse matrix designed to act on the vectori- |
zation of the 3D array. The dimensions of that | zation of the 3D array. The dimensions of that | ||
array are assumed to be ordered as [X Y Z]. | array are assumed to be ordered as [X Y Z]. | ||
==See also== | ==See also== | ||
| − | |||
[[fdvec.m]], [[fdmat.m]], [[fdhess.m]], [[fdkup.m]], [[fdweights.m]], [[fftdiff.m]], [[fourdif.m]], [[fourlap.m]] | [[fdvec.m]], [[fdmat.m]], [[fdhess.m]], [[fdkup.m]], [[fdweights.m]], [[fftdiff.m]], [[fourdif.m]], [[fourlap.m]] | ||
''Version 2.2, authors: [[Ilya Kuprov]]'' | ''Version 2.2, authors: [[Ilya Kuprov]]'' | ||
Revision as of 15:48, 5 April 2026
Returns a finite-difference representation of the Laplacian for an array with a user-specified finite difference stencil size. The resulting operator is a sparse matrix designed to act on the vectorisation of the array. The dimensions of the array are assumed to be ordered as [X Y Z].
Contents
Syntax
L=fdlap(npoints,extents,nstenc)
Arguments
dims - a one-element, two-element, or three-element
vector specifying the number of discretisation
points in each dimension of the 1D, 2D, or 3D
array of data that the operator will be acting
on, ordered as [X Y Z].
extents - a one-element, two-element, or three-element
vector specifying the size of each dimension
of the array, ordered as [X Y Z].
nstenc - number of finite-difference stencil points for
the finite-difference approximation; periodic
boundary conditions are used
Outputs
L - a sparse matrix designed to act on the vectori-
zation of the 3D array. The dimensions of that
array are assumed to be ordered as [X Y Z].
See also
fdvec.m, fdmat.m, fdhess.m, fdkup.m, fdweights.m, fftdiff.m, fourdif.m, fourlap.m
Version 2.2, authors: Ilya Kuprov
