File petsc_laplace.hxx¶

class LaplacePetsc : public Laplacian ¶

Public Functions

LaplacePetsc(Options *opt = nullptr, const CELL_LOC loc = CELL_CENTRE, Mesh *mesh_in = nullptr, Solver *solver = nullptr, Datafile *dump = nullptr)¶

inline virtual void setCoefA(const Field2D &val) override¶: Set coefficients for inversion. Re-builds matrices if necessary.

virtual FieldPerp solve(const FieldPerp &b, const FieldPerp &x0) override¶

Solves Ax=b for x given a b and an initial guess for x (x0)

This function will:

Set the matrix element of the matrix A, used to solve Ax=b (this includes setting the values for the bounary condition)
Solve the matrix Ax = b

Parameters

b – [in] The RHS of the equation Ax=b. This is an y-slice of the original field. The field wil be flattened to an 1D array in order to write the equation on the form Ax=b
x0 – [in] The initial guess for the solver. May also contain the boundary condition if flag 32 - INVERT_SET is set

Returns

sol The solution x of the problem Ax=b.

Private Functions

void Element(int i, int x, int z, int xshift, int zshift, PetscScalar ele, Mat &MatA)¶

Sets the elements of the matrix A, which is used to solve the problem Ax=b.

Parameters

void Coeffs(int x, int y, int z, BoutReal &A1, BoutReal &A2, BoutReal &A3, BoutReal &A4, BoutReal &A5)¶

Set the matrix components of A in Ax=b, solving D*Laplace_perp(x) + (1/C1)Grad_perp(C2)*Grad_perp(x) + Ax = B

Note

“A” in the equation above is not added here. For calculations of the coefficients, please refer to the user manual.

Parameters

x – [in] The current x index
y – [in] The current y index
z – [in] The current y index
coef1 – [in] Placeholder for convenient variable used to set matrix (see manual for details)
coef2 – [in] Convenient variable used to set matrix (see manual for details)
coef3 – [in] Placeholder for convenient variable used to set matrix (see manual for details)
coef4 – [in] Placeholder for convenient variable used to set matrix (see manual for details)
coef5 – [in] Placeholder for convenient variable used to set matrix (see manual for details)
coef1 – [out] Convenient variable used to set matrix (see manual for details)
coef2 – [out] Convenient variable used to set matrix (see manual for details)
coef3 – [out] Convenient variable used to set matrix (see manual for details)
coef4 – [out] Convenient variable used to set matrix (see manual for details)
coef5 – [out] Convenient variable used to set matrix (see manual for details)