1 #include <petscmat.h> 2 #include <petsc/private/matorderimpl.h> 3 #include <amd.h> 4 5 #if defined(PETSC_USE_64BIT_INDICES) 6 #define amd_AMD_defaults amd_l_defaults 7 /* the type casts are needed because PetscInt is long long while SuiteSparse_long is long and compilers warn even when they are identical */ 8 #define amd_AMD_order(a, b, c, d, e, f) amd_l_order((SuiteSparse_long)a, (SuiteSparse_long *)b, (SuiteSparse_long *)c, (SuiteSparse_long *)d, e, f) 9 #else 10 #define amd_AMD_defaults amd_defaults 11 #define amd_AMD_order amd_order 12 #endif 13 14 /* 15 MatGetOrdering_AMD - Find the Approximate Minimum Degree ordering 16 17 This provides an interface to Tim Davis' AMD package (used by UMFPACK, CHOLMOD, MATLAB, etc). 18 */ 19 PETSC_INTERN PetscErrorCode MatGetOrdering_AMD(Mat mat, MatOrderingType type, IS *row, IS *col) 20 { 21 PetscInt nrow, *perm; 22 const PetscInt *ia, *ja; 23 int status; 24 PetscReal val; 25 double Control[AMD_CONTROL], Info[AMD_INFO]; 26 PetscBool tval, done; 27 28 PetscFunctionBegin; 29 /* 30 AMD does not require that the matrix be symmetric (it does so internally, 31 at least in so far as computing orderings for A+A^T. 32 */ 33 PetscCall(MatGetRowIJ(mat, 0, PETSC_FALSE, PETSC_TRUE, &nrow, &ia, &ja, &done)); 34 PetscCheck(done, PETSC_COMM_SELF, PETSC_ERR_SUP, "Cannot get rows for matrix type %s", ((PetscObject)mat)->type_name); 35 36 amd_AMD_defaults(Control); 37 PetscOptionsBegin(PetscObjectComm((PetscObject)mat), ((PetscObject)mat)->prefix, "AMD Options", "Mat"); 38 /* 39 We have to use temporary values here because AMD always uses double, even though PetscReal may be single 40 */ 41 val = (PetscReal)Control[AMD_DENSE]; 42 PetscCall(PetscOptionsReal("-mat_ordering_amd_dense", "threshold for \"dense\" rows/columns", "None", val, &val, NULL)); 43 Control[AMD_DENSE] = (double)val; 44 45 tval = (PetscBool)Control[AMD_AGGRESSIVE]; 46 PetscCall(PetscOptionsBool("-mat_ordering_amd_aggressive", "use aggressive absorption", "None", tval, &tval, NULL)); 47 Control[AMD_AGGRESSIVE] = (double)tval; 48 49 PetscOptionsEnd(); 50 51 PetscCall(PetscMalloc1(nrow, &perm)); 52 status = amd_AMD_order(nrow, ia, ja, perm, Control, Info); 53 switch (status) { 54 case AMD_OK: 55 break; 56 case AMD_OK_BUT_JUMBLED: 57 /* The result is fine, but PETSc matrices are supposed to satisfy stricter preconditions, so PETSc considers a 58 * matrix that triggers this error condition to be invalid. 59 */ 60 SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_PLIB, "According to AMD, the matrix has unsorted and/or duplicate row indices"); 61 case AMD_INVALID: 62 amd_info(Info); 63 SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_PLIB, "According to AMD, the matrix is invalid"); 64 case AMD_OUT_OF_MEMORY: 65 SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_MEM, "AMD could not compute ordering"); 66 default: 67 SETERRQ(PetscObjectComm((PetscObject)mat), PETSC_ERR_LIB, "Unexpected return value"); 68 } 69 PetscCall(MatRestoreRowIJ(mat, 0, PETSC_FALSE, PETSC_TRUE, NULL, &ia, &ja, &done)); 70 71 PetscCall(ISCreateGeneral(PETSC_COMM_SELF, nrow, perm, PETSC_COPY_VALUES, row)); 72 PetscCall(ISCreateGeneral(PETSC_COMM_SELF, nrow, perm, PETSC_OWN_POINTER, col)); 73 PetscFunctionReturn(PETSC_SUCCESS); 74 } 75