Mercurial > repos > public > sbplib

diff stencilEquation.m @ 832:5573913a0949 feature/burgers1d

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Merged with default, and updated +scheme/Burgers1D accordingly
author Vidar Stiernström <vidar.stiernstrom@it.uu.se>
date Tue, 11 Sep 2018 15:58:35 +0200
parents 184833fe4c0e
children
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/stencilEquation.m	Tue Sep 11 15:58:35 2018 +0200
@@ -0,0 +1,13 @@
+% Find the equation for the stencil for d^k/dx^k
+function [A,b] = stencilEquation(k, offsets, order)
+    q = sym('q', [1, length(offsets)]);
+
+    p = 0:(order-1+k);
+
+    v     = vandermonde(offsets, p);
+    vdiff = vandermonde(      0, p-k);
+
+    eq = q*v == vdiff;
+
+    [A,b] = equationsToMatrix(eq, q);
+end