Home Online Manual
Top
Back: u
Forward: laxfrT
FastBack:
FastForward:
Up: finitediff_lib
Top: Singular Manual
Contents: Table of Contents
Index: Index
About: About this document

D.15.13.3 scheme

Procedure from library finitediff.lib (see finitediff_lib).

Usage:
scheme([v1,..,vn]); v1,..,vn of type vector

Return:
poly

Purpose:
performs substitutions by the means of Groebner basis computation of the submodule, generated by the input vectors, then intersects the intermediate result with the suitable component in order to get a finite difference scheme

Note:
works only for a single PDE, for the case of a system use matrixsystem

Example:
 
LIB "finitediff.lib";
list D="Ux","Ut","U";
list P="a";
list V="t","x";
setinitials(V,D,P);
def s1=scheme(u(Ut)+a*u(Ux),backward(Ux,U,x),forward(Ut,U,t));
s1;
==> (-a*dt+dx)/(dx)*x+(a*dt)/(dx)