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D.15.4.4 laxfrT
Procedure from library finitediff.lib (see finitediff_lib).
- Usage:
- laxfrT(U1,U2,var); U1, U2 are the names of occuring derivatives, var is a variable in the basering;
- Return:
- type vector; gives a predefined approximation of the Lax-Friedrich-approximation for the derivation in the timevariable as often used in literature;
- Note:
- see also laxfrX, setinitials, scheme; Warning: laxfrT is not to be interchanged with laxfrX
Example:
| LIB "finitediff.lib";
list D="Ux","Ut","U";
list P="a";
list V="t","x";
setinitials(V,D,P);
laxfrT(Ux,U,x);
==> [(dt)*x,0,-t*x+1/2*x^2+1/2]
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