public Vector getRealU() {
// 4.Weak form
WeakFormLaplace2D weakForm = new WeakFormLaplace2D();
plotFunction(mesh, coef_q, "qReal.dat");
weakForm.setParam(coef_q, FC.C0, null, null);
// Right hand side(RHS): f(x) = -4.0
weakForm.setF(FC.c(-4.0));
// 5.Assembly process
AssemblerScalar assembler = new AssemblerScalar(mesh, weakForm);
System.out.println("Begin Assemble...");
assembler.assemble();
SparseMatrix stiff = assembler.getStiffnessMatrix();
SparseVector load = assembler.getLoadVector();
// Boundary condition
assembler.imposeDirichletCondition(diri);
System.out.println("Assemble done!");
// 6.Solve linear system
Solver solver = new Solver();
Vector u = solver.solveCG(stiff, load);
System.out.println("u=");
for (int i = 1; i <= u.getDim(); i++) System.out.println(String.format("%.3f", u.get(i)));
plotVector(mesh, u, "uReal.dat");
return u;
}
