Trapezoid.C
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25 
26 #include "Trapezoid.H"
28 
29 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
30 
31 namespace Foam
32 {
33  defineTypeNameAndDebug(Trapezoid, 0);
34  addToRunTimeSelectionTable(ODESolver, Trapezoid, dictionary);
35 }
36 
37 
38 // * * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * //
39 
41 :
42  ODESolver(ode, dict),
43  adaptiveSolver(ode, dict),
44  err_(n_)
45 {}
46 
47 
48 // * * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * //
49 
50 Foam::scalar Foam::Trapezoid::solve
51 (
52  const scalar x0,
53  const scalarField& y0,
54  const scalarField& dydx0,
55  const scalar dx,
56  scalarField& y
57 ) const
58 {
59  // Predict the state using 1st-order Trapezoid method
60  forAll(y, i)
61  {
62  y[i] = y0[i] + dx*dydx0[i];
63  }
64 
65  // Evaluate the system for the predicted state
66  odes_.derivatives(x0 + dx, y, err_);
67 
68  // Update the state as the average between the prediction and the correction
69  // and estimate the error from the difference
70  forAll(y, i)
71  {
72  y[i] = y0[i] + 0.5*dx*(dydx0[i] + err_[i]);
73  err_[i] = 0.5*dx*(err_[i] - dydx0[i]);
74  }
75 
76  return normalizeError(y0, y, err_);
77 }
78 
79 
81 (
82  scalar& x,
83  scalarField& y,
84  scalar& dxTry
85 ) const
86 {
87  adaptiveSolver::solve(odes_, x, y, dxTry);
88 }
89 
90 
91 // ************************************************************************* //
virtual scalar solve(const scalar x0, const scalarField &y0, const scalarField &dydx0, const scalar dx, scalarField &y) const =0
Solve a single step dx and return the error.
A list of keyword definitions, which are a keyword followed by any number of values (e...
Definition: dictionary.H:137
virtual void derivatives(const scalar x, const scalarField &y, scalarField &dydx) const =0
Calculate the derivatives in dydx.
Namespace for OpenFOAM.
Abstract base class for the systems of ordinary differential equations.
Definition: ODESystem.H:46
dictionary dict
An ODE solver for chemistry.
Definition: ode.H:50
#define forAll(list, i)
Definition: UList.H:421
const ODESystem & odes_
Reference to ODESystem.
Definition: ODESolver.H:58
Macros for easy insertion into run-time selection tables.
Trapezoid(const ODESystem &ode, const dictionary &dict)
Construct from ODE.
Definition: Trapezoid.C:40
Abstract base-class for ODE system solvers.
Definition: ODESolver.H:50
scalar normalizeError(const scalarField &y0, const scalarField &y, const scalarField &err) const
Return the nomalized scalar error.
Definition: ODESolver.C:67
addToRunTimeSelectionTable(ensightPart, ensightPartCells, istream)
scalar solve(const scalar x0, const scalarField &y0, const scalarField &dydx0, const scalar dx, scalarField &y) const
Solve a single step dx and return the error.
Definition: Trapezoid.C:51
defineTypeNameAndDebug(combustionModel, 0)