1 2 #include <private/snesimpl.h> /*I "petscsnes.h" I*/ 3 #include <../src/mat/impls/mffd/mffdimpl.h> 4 #include <private/matimpl.h> 5 6 #undef __FUNCT__ 7 #define __FUNCT__ "MatMFFDComputeJacobian" 8 /*@C 9 MatMFFDComputeJacobian - Tells the matrix-free Jacobian object the new location at which 10 Jacobian matrix vector products will be computed at, i.e. J(x) * a. The x is obtained 11 from the SNES object (using SNESGetSolution()). 12 13 Logically Collective on SNES 14 15 Input Parameters: 16 + snes - the nonlinear solver context 17 . x - the point at which the Jacobian vector products will be performed 18 . jac - the matrix-free Jacobian object 19 . B - either the same as jac or another matrix type (ignored) 20 . flag - not relevent for matrix-free form 21 - dummy - the user context (ignored) 22 23 Level: developer 24 25 Warning: 26 If MatMFFDSetBase() is ever called on jac then this routine will NO longer get 27 the x from the SNES object and MatMFFDSetBase() must from that point on be used to 28 change the base vector x. 29 30 Notes: 31 This can be passed into SNESSetJacobian() when using a completely matrix-free solver, 32 that is the B matrix is also the same matrix operator. This is used when you select 33 -snes_mf but rarely used directly by users. (All this routine does is call MatAssemblyBegin/End() on 34 the Mat jac. 35 36 .seealso: MatMFFDGetH(), MatCreateSNESMF(), MatCreateMFFD(), MATMFFD, 37 MatMFFDSetHHistory(), MatMFFDSetFunctionError(), MatCreateMFFD(), SNESSetJacobian() 38 39 @*/ 40 PetscErrorCode MatMFFDComputeJacobian(SNES snes,Vec x,Mat *jac,Mat *B,MatStructure *flag,void *dummy) 41 { 42 PetscErrorCode ierr; 43 PetscFunctionBegin; 44 ierr = MatAssemblyBegin(*jac,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 45 ierr = MatAssemblyEnd(*jac,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); 46 PetscFunctionReturn(0); 47 } 48 49 PetscErrorCode MatAssemblyEnd_MFFD(Mat,MatAssemblyType); 50 EXTERN_C_BEGIN 51 PetscErrorCode MatMFFDSetBase_MFFD(Mat,Vec,Vec); 52 EXTERN_C_END 53 54 #undef __FUNCT__ 55 #define __FUNCT__ "MatAssemblyEnd_SNESMF" 56 /* 57 MatAssemblyEnd_SNESMF - Calls MatAssemblyEnd_MFFD() and then sets the 58 base from the SNES context 59 60 */ 61 PetscErrorCode MatAssemblyEnd_SNESMF(Mat J,MatAssemblyType mt) 62 { 63 PetscErrorCode ierr; 64 MatMFFD j = (MatMFFD)J->data; 65 SNES snes = (SNES)j->funcctx; 66 67 PetscFunctionBegin; 68 ierr = MatAssemblyEnd_MFFD(J,mt);CHKERRQ(ierr); 69 70 ierr = SNESGetSolution(snes,&u);CHKERRQ(ierr); 71 ierr = SNESGetFunction(snes,&f,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr); 72 ierr = SNESGetSolution(snes,&j->current_u);CHKERRQ(ierr); 73 ierr = SNESGetFunction(snes,&j->current_f,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr); 74 j->current_f_allocated = PETSC_FALSE; 75 if (!j->w) { 76 ierr = VecDuplicate(j->current_u, &j->w);CHKERRQ(ierr); 77 } 78 PetscFunctionReturn(0); 79 } 80 81 EXTERN_C_BEGIN 82 /* 83 This routine resets the MatAssemblyEnd() for the MatMFFD created from MatCreateSNESMF() so that it NO longer 84 uses the solution in the SNES object to update the base. See the warning in MatCreateSNESMF(). 85 */ 86 #undef __FUNCT__ 87 #define __FUNCT__ "MatMFFDSetBase_SNESMF" 88 PetscErrorCode MatMFFDSetBase_SNESMF(Mat J,Vec U,Vec F) 89 { 90 PetscErrorCode ierr; 91 92 PetscFunctionBegin; 93 ierr = MatMFFDSetBase_MFFD(J,U,F);CHKERRQ(ierr); 94 J->ops->assemblyend = MatAssemblyEnd_MFFD; 95 PetscFunctionReturn(0); 96 } 97 EXTERN_C_END 98 99 #undef __FUNCT__ 100 #define __FUNCT__ "MatCreateSNESMF" 101 /*@ 102 MatCreateSNESMF - Creates a matrix-free matrix context for use with 103 a SNES solver. This matrix can be used as the Jacobian argument for 104 the routine SNESSetJacobian(). See MatCreateMFFD() for details on how 105 the finite difference computation is done. 106 107 Collective on SNES and Vec 108 109 Input Parameters: 110 . snes - the SNES context 111 112 Output Parameter: 113 . J - the matrix-free matrix 114 115 Level: advanced 116 117 Warning: 118 If MatMFFDSetBase() is ever called on jac then this routine will NO longer get 119 the x from the SNES object and MatMFFDSetBase() must from that point on be used to 120 change the base vector x. 121 122 Notes: The difference between this routine and MatCreateMFFD() is that this matrix 123 automatically gets the current base vector from the SNES object and not from an 124 explicit call to MatMFFDSetBase(). 125 126 .seealso: MatDestroy(), MatMFFDSetFunctionError(), MatMFFDDSSetUmin() 127 MatMFFDSetHHistory(), MatMFFDResetHHistory(), MatCreateMFFD(), 128 MatMFFDGetH(), MatMFFDRegisterDynamic), MatMFFDComputeJacobian() 129 130 @*/ 131 PetscErrorCode MatCreateSNESMF(SNES snes,Mat *J) 132 { 133 PetscErrorCode ierr; 134 PetscInt n,N; 135 136 PetscFunctionBegin; 137 if (snes->vec_func) { 138 ierr = VecGetLocalSize(snes->vec_func,&n);CHKERRQ(ierr); 139 ierr = VecGetSize(snes->vec_func,&N);CHKERRQ(ierr); 140 } else if (snes->dm) { 141 Vec tmp; 142 ierr = DMGetGlobalVector(snes->dm,&tmp);CHKERRQ(ierr); 143 ierr = VecGetLocalSize(tmp,&n);CHKERRQ(ierr); 144 ierr = VecGetSize(tmp,&N);CHKERRQ(ierr); 145 ierr = DMRestoreGlobalVector(snes->dm,&tmp);CHKERRQ(ierr); 146 } else SETERRQ(((PetscObject)snes)->comm,PETSC_ERR_ARG_WRONGSTATE,"Must call SNESSetFunction() or SNESSetDM() first"); 147 ierr = MatCreateMFFD(((PetscObject)snes)->comm,n,n,N,N,J);CHKERRQ(ierr); 148 ierr = MatMFFDSetFunction(*J,(PetscErrorCode (*)(void*,Vec,Vec))SNESComputeFunction,snes);CHKERRQ(ierr); 149 (*J)->ops->assemblyend = MatAssemblyEnd_SNESMF; 150 ierr = PetscObjectComposeFunctionDynamic((PetscObject)*J,"MatMFFDSetBase_C","MatMFFDSetBase_SNESMF",MatMFFDSetBase_SNESMF);CHKERRQ(ierr); 151 PetscFunctionReturn(0); 152 } 153 154 155 156 157 158 159