1 #ifndef PETSCGL_H 2 #define PETSCGL_H 3 4 #include <petsc/private/tsimpl.h> 5 6 typedef enum { 7 TSGLLEERROR_FORWARD, 8 TSGLLEERROR_BACKWARD 9 } TSGLLEErrorDirection; 10 11 typedef struct _TSGLLEScheme *TSGLLEScheme; 12 struct _TSGLLEScheme { 13 PetscInt p; /* order of the method */ 14 PetscInt q; /* stage-order of the method */ 15 PetscInt r; /* number of items carried between stages */ 16 PetscInt s; /* number of stages */ 17 PetscScalar *c; /* location of the stages */ 18 PetscScalar *a, *b, *u, *v; /* tableau for the method */ 19 20 /* For use in rescale & modify */ 21 PetscScalar *alpha; /* X_n(t_n) - X_{n-1}(t_n) = - alpha^T h^{p+1} x^{(p+1)}(t_n) */ 22 PetscScalar *beta; /* - beta^T h^{p+2} x^{(p+2)}(t_n) */ 23 PetscScalar *gamma; /* - gamma^T h^{p+2} f' x^{(p+1)}(t_n) + O(h^{p+3}) */ 24 25 /* Error estimates */ 26 /* h^{p+1}x^{(p+1)}(t_n) ~= phi[0]*h*Ydot + psi[0]*X[1:] */ 27 /* h^{p+2}x^{(p+2)}(t_n) ~= phi[1]*h*Ydot + psi[1]*X[1:] */ 28 /* h^{p+2}f' x^{(p+1)}(t_n) ~= phi[2]*h*Ydot + psi[2]*X[1:] */ 29 PetscScalar *phi; /* dim=[3][s] for estimating higher moments, see B,J,W 2007 */ 30 PetscScalar *psi; /* dim=[3][r-1], [0 psi^T] of B,J,W 2007 */ 31 PetscScalar *stage_error; 32 33 /* Desirable properties which enable extra optimizations */ 34 PetscBool stiffly_accurate; /* Last row of [A U] is equal t first row of [B V]? */ 35 PetscBool fsal; /* First Same As Last: X[1] = h*Ydot[s-1] (and stiffly accurate) */ 36 }; 37 38 typedef struct TS_GLLE { 39 TSGLLEAcceptFunction Accept; /* Decides whether to accept a given time step, given estimates of local truncation error */ 40 TSGLLEAdapt adapt; 41 42 /* These names are only stored so that they can be printed in TSView_GLLE() without making these schemes full-blown 43 objects (the implementations I'm thinking of do not have state and I'm lazy). */ 44 char accept_name[256]; 45 46 /* specific to the family of GL method */ 47 PetscErrorCode (*EstimateHigherMoments)(TSGLLEScheme, PetscReal, Vec *, Vec *, Vec *); /* Provide local error estimates */ 48 PetscErrorCode (*CompleteStep)(TSGLLEScheme, PetscReal, TSGLLEScheme, PetscReal, Vec *, Vec *, Vec *); 49 PetscErrorCode (*Destroy)(struct TS_GLLE *); 50 PetscErrorCode (*View)(struct TS_GLLE *, PetscViewer); 51 char type_name[256]; 52 PetscInt nschemes; 53 TSGLLEScheme *schemes; 54 55 Vec *X; /* Items to carry between steps */ 56 Vec *Xold; /* Values of these items at the last step */ 57 Vec W; /* = 1/(atol+rtol*|X0|), used for WRMS norm */ 58 Vec *himom; /* len=3, Estimates of h^{p+1}x^{(p+1)}, h^{p+2}x^{(p+2)}, h^{p+2}(df/dx) x^{(p+1)} */ 59 PetscReal wrms_atol, wrms_rtol; 60 61 /* Stages (Y,Ydot) are computed sequentially */ 62 Vec *Ydot; /* Derivatives of stage vectors, must be stored */ 63 Vec Y; /* Stage vector, only used while solving the stage so we don't need to store it */ 64 Vec Z; /* Affine vector */ 65 PetscReal scoeff; /* Ydot = Z + shift*Y; shift = scoeff/ts->time_step */ 66 PetscReal stage_time; /* time at current stage */ 67 PetscInt stage; /* index of the stage we are currently solving for */ 68 69 /* Runtime options */ 70 PetscInt current_scheme; 71 PetscInt max_order, min_order, start_order; 72 PetscBool extrapolate; /* use extrapolation to produce initial Newton iterate? */ 73 TSGLLEErrorDirection error_direction; /* TSGLLEERROR_FORWARD or TSGLLEERROR_BACKWARD */ 74 75 PetscInt max_step_rejections; 76 77 PetscBool setupcalled; 78 void *data; 79 } TS_GLLE; 80 81 #endif 82