xref: /petsc/include/petscis.h (revision 4e1d6e842c3d3ab5ca8f150f103947d8f9e4cedd)

/*
   An index set is a generalization of a subset of integers.  Index sets
   are used for defining scatters and gathers.
*/
#if !defined(PETSCIS_H)
#define PETSCIS_H
#include <petscsys.h>
#include <petscsftypes.h>
#include <petscsectiontypes.h>
#include <petscistypes.h>    /*I  "petscis.h" I*/

#define IS_FILE_CLASSID 1211218
PETSC_EXTERN PetscClassId IS_CLASSID;

PETSC_EXTERN PetscErrorCode ISInitializePackage(void);

/*J
    ISType - String with the name of a PETSc index set type

   Level: beginner

.seealso: ISSetType(), IS, ISCreate(), ISRegister()
J*/
typedef const char* ISType;
#define ISGENERAL      "general"
#define ISSTRIDE       "stride"
#define ISBLOCK        "block"

/* Dynamic creation and loading functions */
PETSC_EXTERN PetscFunctionList ISList;
PETSC_EXTERN PetscErrorCode ISSetType(IS, ISType);
PETSC_EXTERN PetscErrorCode ISGetType(IS, ISType *);
PETSC_EXTERN PetscErrorCode ISRegister(const char[],PetscErrorCode (*)(IS));
PETSC_EXTERN PetscErrorCode ISCreate(MPI_Comm,IS*);

PETSC_EXTERN PetscErrorCode ISDestroy(IS*);
PETSC_EXTERN PetscErrorCode ISSetPermutation(IS);
PETSC_EXTERN PetscErrorCode ISPermutation(IS,PetscBool *);
PETSC_EXTERN PetscErrorCode ISSetIdentity(IS);
PETSC_EXTERN PetscErrorCode ISIdentity(IS,PetscBool *);
PETSC_EXTERN PetscErrorCode ISContiguousLocal(IS,PetscInt,PetscInt,PetscInt*,PetscBool*);

/*E
    ISInfo - Info that may either be computed or set as known for an index set

    Level: beginner

   Any additions/changes here MUST also be made in include/petsc/finclude/petscis.h
   Any additions/changes here must also be made in src/vec/vec/interface/dlregisvec.c in ISInfos[]

   Developer Notes:
    Entries that are negative need not be called collectively by all processes.

.seealso: ISSetInfo()
E*/
typedef enum {IS_INFO_MIN = -1,
              IS_SORTED = 0,
              IS_UNIQUE = 1,
              IS_PERMUTATION = 2,
              IS_INTERVAL = 3,
              IS_IDENTITY = 4,
              IS_INFO_MAX = 5} ISInfo;

typedef enum {IS_LOCAL, IS_GLOBAL} ISInfoType;

PETSC_EXTERN PetscErrorCode ISSetInfo(IS,ISInfo,ISInfoType,PetscBool,PetscBool);
PETSC_EXTERN PetscErrorCode ISGetInfo(IS,ISInfo,ISInfoType,PetscBool,PetscBool*);
PETSC_EXTERN PetscErrorCode ISClearInfoCache(IS,PetscBool);
PETSC_EXTERN PetscErrorCode ISGetIndices(IS,const PetscInt *[]);
PETSC_EXTERN PetscErrorCode ISRestoreIndices(IS,const PetscInt *[]);
PETSC_EXTERN PetscErrorCode ISGetTotalIndices(IS,const PetscInt *[]);
PETSC_EXTERN PetscErrorCode ISRestoreTotalIndices(IS,const PetscInt *[]);
PETSC_EXTERN PetscErrorCode ISGetNonlocalIndices(IS,const PetscInt *[]);
PETSC_EXTERN PetscErrorCode ISRestoreNonlocalIndices(IS,const PetscInt *[]);
PETSC_EXTERN PetscErrorCode ISGetNonlocalIS(IS, IS *is);
PETSC_EXTERN PetscErrorCode ISRestoreNonlocalIS(IS, IS *is);
PETSC_EXTERN PetscErrorCode ISGetSize(IS,PetscInt *);
PETSC_EXTERN PetscErrorCode ISGetLocalSize(IS,PetscInt *);
PETSC_EXTERN PetscErrorCode ISInvertPermutation(IS,PetscInt,IS*);
PETSC_EXTERN PetscErrorCode ISView(IS,PetscViewer);
PETSC_EXTERN PetscErrorCode ISViewFromOptions(IS,PetscObject,const char[]);
PETSC_EXTERN PetscErrorCode ISLoad(IS,PetscViewer);
PETSC_EXTERN PetscErrorCode ISEqual(IS,IS,PetscBool  *);
PETSC_EXTERN PetscErrorCode ISEqualUnsorted(IS,IS,PetscBool *);
PETSC_EXTERN PetscErrorCode ISSort(IS);
PETSC_EXTERN PetscErrorCode ISSortRemoveDups(IS);
PETSC_EXTERN PetscErrorCode ISSorted(IS,PetscBool  *);
PETSC_EXTERN PetscErrorCode ISDifference(IS,IS,IS*);
PETSC_EXTERN PetscErrorCode ISSum(IS,IS,IS*);
PETSC_EXTERN PetscErrorCode ISExpand(IS,IS,IS*);
PETSC_EXTERN PetscErrorCode ISIntersect(IS,IS,IS*);
PETSC_EXTERN PetscErrorCode ISGetMinMax(IS,PetscInt*,PetscInt*);

PETSC_EXTERN PetscErrorCode ISLocate(IS,PetscInt,PetscInt*);
PETSC_EXTERN PetscErrorCode ISGetPointRange(IS,PetscInt*,PetscInt*,const PetscInt**);
PETSC_EXTERN PetscErrorCode ISRestorePointRange(IS,PetscInt*,PetscInt*,const PetscInt**);
PETSC_EXTERN PetscErrorCode ISGetPointSubrange(IS,PetscInt,PetscInt,const PetscInt*);

PETSC_EXTERN PetscErrorCode ISGetBlockSize(IS,PetscInt*);
PETSC_EXTERN PetscErrorCode ISSetBlockSize(IS,PetscInt);

PETSC_EXTERN PetscErrorCode ISToGeneral(IS);

PETSC_EXTERN PetscErrorCode ISDuplicate(IS,IS*);
PETSC_EXTERN PetscErrorCode ISCopy(IS,IS);
PETSC_EXTERN PetscErrorCode ISAllGather(IS,IS*);
PETSC_EXTERN PetscErrorCode ISComplement(IS,PetscInt,PetscInt,IS*);
PETSC_EXTERN PetscErrorCode ISConcatenate(MPI_Comm,PetscInt,const IS[],IS*);
PETSC_EXTERN PetscErrorCode ISListToPair(MPI_Comm,PetscInt, IS[],IS*,IS*);
PETSC_EXTERN PetscErrorCode ISPairToList(IS,IS,PetscInt*, IS *[]);
PETSC_EXTERN PetscErrorCode ISEmbed(IS,IS,PetscBool,IS*);
PETSC_EXTERN PetscErrorCode ISSortPermutation(IS,PetscBool,IS*);
PETSC_EXTERN PetscErrorCode ISOnComm(IS,MPI_Comm,PetscCopyMode,IS*);
PETSC_EXTERN PetscErrorCode ISRenumber(IS,IS,PetscInt*,IS*);
PETSC_EXTERN PetscErrorCode ISCreateSubIS(IS,IS,IS*);

/* ISGENERAL specific */
PETSC_EXTERN PetscErrorCode ISCreateGeneral(MPI_Comm,PetscInt,const PetscInt[],PetscCopyMode,IS *);
PETSC_EXTERN PetscErrorCode ISGeneralSetIndices(IS,PetscInt,const PetscInt[],PetscCopyMode);
PETSC_EXTERN PetscErrorCode ISGeneralSetIndicesFromMask(IS,PetscInt,PetscInt,const PetscBool[]);
PETSC_EXTERN PetscErrorCode ISGeneralFilter(IS,PetscInt,PetscInt);

/* ISBLOCK specific */
PETSC_EXTERN PetscErrorCode ISCreateBlock(MPI_Comm,PetscInt,PetscInt,const PetscInt[],PetscCopyMode,IS *);
PETSC_EXTERN PetscErrorCode ISBlockSetIndices(IS,PetscInt,PetscInt,const PetscInt[],PetscCopyMode);
PETSC_EXTERN PetscErrorCode ISBlockGetIndices(IS,const PetscInt *[]);
PETSC_EXTERN PetscErrorCode ISBlockRestoreIndices(IS,const PetscInt *[]);
PETSC_EXTERN PetscErrorCode ISBlockGetLocalSize(IS,PetscInt *);
PETSC_EXTERN PetscErrorCode ISBlockGetSize(IS,PetscInt *);

/* ISSTRIDE specific */
PETSC_EXTERN PetscErrorCode ISCreateStride(MPI_Comm,PetscInt,PetscInt,PetscInt,IS *);
PETSC_EXTERN PetscErrorCode ISStrideSetStride(IS,PetscInt,PetscInt,PetscInt);
PETSC_EXTERN PetscErrorCode ISStrideGetInfo(IS,PetscInt *,PetscInt*);

/* --------------------------------------------------------------------------*/
PETSC_EXTERN PetscClassId IS_LTOGM_CLASSID;

/*E
    ISGlobalToLocalMappingMode - Indicates mapping behavior if global indices are missing

   IS_GTOLM_MASK - missing global indices are masked by mapping them to a local index of -1
   IS_GTOLM_DROP - missing global indices are dropped

   Level: beginner

.seealso: ISGlobalToLocalMappingApplyBlock(), ISGlobalToLocalMappingApply()

E*/
typedef enum {IS_GTOLM_MASK,IS_GTOLM_DROP} ISGlobalToLocalMappingMode;

/*J
    ISLocalToGlobalMappingType - String with the name of a mapping method

   Level: beginner

.seealso: ISLocalToGlobalMappingSetType(), ISLocalToGlobalSetFromOptions()
J*/
typedef const char* ISLocalToGlobalMappingType;
#define ISLOCALTOGLOBALMAPPINGBASIC "basic"
#define ISLOCALTOGLOBALMAPPINGHASH  "hash"

PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingSetType(ISLocalToGlobalMapping,ISLocalToGlobalMappingType);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingRegister(const char[],PetscErrorCode (*)(ISLocalToGlobalMapping));
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingRegisterAll(void);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingCreate(MPI_Comm,PetscInt,PetscInt,const PetscInt[],PetscCopyMode,ISLocalToGlobalMapping*);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingCreateIS(IS,ISLocalToGlobalMapping *);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingCreateSF(PetscSF,PetscInt,ISLocalToGlobalMapping*);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingSetFromOptions(ISLocalToGlobalMapping);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingSetUp(ISLocalToGlobalMapping);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingView(ISLocalToGlobalMapping,PetscViewer);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingViewFromOptions(ISLocalToGlobalMapping,PetscObject,const char[]);

PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingDestroy(ISLocalToGlobalMapping*);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingApply(ISLocalToGlobalMapping,PetscInt,const PetscInt[],PetscInt[]);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingApplyBlock(ISLocalToGlobalMapping,PetscInt,const PetscInt[],PetscInt[]);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingApplyIS(ISLocalToGlobalMapping,IS,IS*);
PETSC_EXTERN PetscErrorCode ISGlobalToLocalMappingApply(ISLocalToGlobalMapping,ISGlobalToLocalMappingMode,PetscInt,const PetscInt[],PetscInt*,PetscInt[]);
PETSC_EXTERN PetscErrorCode ISGlobalToLocalMappingApplyBlock(ISLocalToGlobalMapping,ISGlobalToLocalMappingMode,PetscInt,const PetscInt[],PetscInt*,PetscInt[]);
PETSC_EXTERN PetscErrorCode ISGlobalToLocalMappingApplyIS(ISLocalToGlobalMapping,ISGlobalToLocalMappingMode,IS,IS*);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingGetSize(ISLocalToGlobalMapping,PetscInt*);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingGetNodeInfo(ISLocalToGlobalMapping,PetscInt*,PetscInt*[],PetscInt**[]);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingRestoreNodeInfo(ISLocalToGlobalMapping,PetscInt*,PetscInt*[],PetscInt**[]);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingGetInfo(ISLocalToGlobalMapping,PetscInt*,PetscInt*[],PetscInt*[],PetscInt**[]);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingRestoreInfo(ISLocalToGlobalMapping,PetscInt*,PetscInt*[],PetscInt*[],PetscInt**[]);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingGetBlockInfo(ISLocalToGlobalMapping,PetscInt*,PetscInt*[],PetscInt*[],PetscInt**[]);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingRestoreBlockInfo(ISLocalToGlobalMapping,PetscInt*,PetscInt*[],PetscInt*[],PetscInt**[]);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingGetIndices(ISLocalToGlobalMapping,const PetscInt**);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingRestoreIndices(ISLocalToGlobalMapping,const PetscInt**);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingGetBlockIndices(ISLocalToGlobalMapping,const PetscInt**);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingRestoreBlockIndices(ISLocalToGlobalMapping,const PetscInt**);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingConcatenate(MPI_Comm,PetscInt,const ISLocalToGlobalMapping[],ISLocalToGlobalMapping*);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingGetBlockSize(ISLocalToGlobalMapping,PetscInt*);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingSetBlockSize(ISLocalToGlobalMapping,PetscInt);
PETSC_EXTERN PetscErrorCode ISLocalToGlobalMappingDuplicate(ISLocalToGlobalMapping,ISLocalToGlobalMapping*);

/* --------------------------------------------------------------------------*/
/*E
    ISColoringType - determines if the coloring is for the entire parallel grid/graph/matrix
                     or for just the local ghosted portion

    Level: beginner

$   IS_COLORING_GLOBAL - does not include the colors for ghost points, this is used when the function
$                        is called synchronously in parallel. This requires generating a "parallel coloring".
$   IS_COLORING_LOCAL - includes colors for ghost points, this is used when the function can be called
$                         separately on individual processes with the ghost points already filled in. Does not
$                         require a "parallel coloring", rather each process colors its local + ghost part.
$                         Using this can result in much less parallel communication. Currently only works
$                         with DMDA and if you call MatFDColoringSetFunction() with the local function.

.seealso: DMCreateColoring()
E*/
typedef enum {IS_COLORING_GLOBAL,IS_COLORING_LOCAL} ISColoringType;
PETSC_EXTERN const char *const ISColoringTypes[];
typedef unsigned PETSC_IS_COLORING_VALUE_TYPE ISColoringValue;
#define IS_COLORING_MAX PETSC_IS_COLORING_MAX
#define MPIU_COLORING_VALUE PETSC_MPIU_IS_COLORING_VALUE_TYPE
PETSC_EXTERN PetscErrorCode ISAllGatherColors(MPI_Comm,PetscInt,ISColoringValue*,PetscInt*,ISColoringValue*[]);

PETSC_EXTERN PetscErrorCode ISColoringCreate(MPI_Comm,PetscInt,PetscInt,const ISColoringValue[],PetscCopyMode,ISColoring*);
PETSC_EXTERN PetscErrorCode ISColoringDestroy(ISColoring*);
PETSC_EXTERN PetscErrorCode ISColoringView(ISColoring,PetscViewer);
PETSC_EXTERN PetscErrorCode ISColoringViewFromOptions(ISColoring,PetscObject,const char[]);
PETSC_EXTERN PetscErrorCode ISColoringGetIS(ISColoring,PetscCopyMode,PetscInt*,IS*[]);
PETSC_EXTERN PetscErrorCode ISColoringRestoreIS(ISColoring,PetscCopyMode,IS*[]);
PETSC_EXTERN PetscErrorCode ISColoringReference(ISColoring);
PETSC_EXTERN PetscErrorCode ISColoringSetType(ISColoring,ISColoringType);
PETSC_EXTERN PetscErrorCode ISColoringGetType(ISColoring,ISColoringType*);
PETSC_EXTERN PetscErrorCode ISColoringGetColors(ISColoring,PetscInt*,PetscInt*,const ISColoringValue**);

/* --------------------------------------------------------------------------*/
PETSC_EXTERN PetscErrorCode ISBuildTwoSided(IS,IS,IS*);
PETSC_EXTERN PetscErrorCode ISPartitioningToNumbering(IS,IS*);
PETSC_EXTERN PetscErrorCode ISPartitioningCount(IS,PetscInt,PetscInt[]);

PETSC_EXTERN PetscErrorCode ISCompressIndicesGeneral(PetscInt,PetscInt,PetscInt,PetscInt,const IS[],IS[]);
PETSC_EXTERN PetscErrorCode ISCompressIndicesSorted(PetscInt,PetscInt,PetscInt,const IS[],IS[]);
PETSC_EXTERN PetscErrorCode ISExpandIndicesGeneral(PetscInt,PetscInt,PetscInt,PetscInt,const IS[],IS[]);

struct _n_PetscLayout{
  MPI_Comm               comm;
  PetscMPIInt            size;
  PetscInt               n,N;         /* local, global vector size */
  PetscInt               rstart,rend; /* local start, local end + 1 */
  PetscInt               *range;      /* the offset of each processor */
  PetscBool              range_alloc; /* should range be freed in Destroy? */
  PetscInt               bs;          /* number of elements in each block (generally for multi-component
                                       * problems). Defaults to -1 and can be arbitrarily lazy so always use
                                       * PetscAbs(map->bs) when accessing directly and expecting result to be
                                       * positive. Do NOT multiply above numbers by bs */
  PetscInt               refcnt;      /* MPI Vecs obtained with VecDuplicate() and from MatCreateVecs() reuse map of input object */
  ISLocalToGlobalMapping mapping;     /* mapping used in Vec/MatSetValuesLocal() */
  PetscBool              setupcalled; /* Forbid setup more than once */
  PetscInt               oldn,oldN;   /* Checking if setup is allowed */
  PetscInt               oldbs;       /* And again */
};

/*@C
     PetscLayoutFindOwner - Find the owning rank for a global index

    Not Collective

   Input Parameters:
+    map - the layout
-    idx - global index to find the owner of

   Output Parameter:
.    owner - the owning rank

   Level: developer

    Fortran Notes:
      Not available from Fortran

@*/
static inline PetscErrorCode PetscLayoutFindOwner(PetscLayout map,PetscInt idx,PetscMPIInt *owner)
{
  PetscMPIInt lo = 0,hi,t;

  PetscFunctionBegin;
  *owner = -1;                  /* GCC erroneously issues warning about possibly uninitialized use when error condition */
#if defined(PETSC_USE_DEBUG)
  PetscCheck((map->n >= 0) && (map->N >= 0) && (map->range),PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"PetscLayoutSetUp() must be called first");
  PetscCheck(idx >= 0 && idx <= map->N,PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Index %" PetscInt_FMT " is out of range",idx);
#endif
  hi = map->size;
  while (hi - lo > 1) {
    t = lo + (hi - lo) / 2;
    if (idx < map->range[t]) hi = t;
    else                     lo = t;
  }
  *owner = lo;
  PetscFunctionReturn(0);
}

/*@C
     PetscLayoutFindOwnerIndex - Find the owning rank and the local index for a global index

    Not Collective

   Input Parameters:
+    map   - the layout
-    idx   - global index to find the owner of

   Output Parameters:
+    owner - the owning rank
-    lidx  - local index used by the owner for idx

   Level: developer

    Fortran Notes:
      Not available from Fortran

@*/
static inline PetscErrorCode PetscLayoutFindOwnerIndex(PetscLayout map,PetscInt idx,PetscMPIInt *owner,PetscInt *lidx)
{
  PetscMPIInt lo = 0,hi,t;

  PetscFunctionBegin;
#if defined(PETSC_USE_DEBUG)
  PetscCheck((map->n >= 0) && (map->N >= 0) && (map->range),PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"PetscLayoutSetUp() must be called first");
  PetscCheck(idx >= 0 && idx <= map->N,PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Index %" PetscInt_FMT " is out of range",idx);
#endif
  hi = map->size;
  while (hi - lo > 1) {
    t = lo + (hi - lo) / 2;
    if (idx < map->range[t]) hi = t;
    else                     lo = t;
  }
  if (owner) *owner = lo;
  if (lidx) *lidx  = idx - map->range[lo];
  PetscFunctionReturn(0);
}

PETSC_EXTERN PetscErrorCode PetscLayoutCreate(MPI_Comm,PetscLayout*);
PETSC_EXTERN PetscErrorCode PetscLayoutCreateFromSizes(MPI_Comm,PetscInt,PetscInt,PetscInt,PetscLayout*);
PETSC_EXTERN PetscErrorCode PetscLayoutCreateFromRanges(MPI_Comm,const PetscInt[],PetscCopyMode,PetscInt,PetscLayout*);
PETSC_EXTERN PetscErrorCode PetscLayoutSetUp(PetscLayout);
PETSC_EXTERN PetscErrorCode PetscLayoutDestroy(PetscLayout*);
PETSC_EXTERN PetscErrorCode PetscLayoutDuplicate(PetscLayout,PetscLayout*);
PETSC_EXTERN PetscErrorCode PetscLayoutReference(PetscLayout,PetscLayout*);
PETSC_EXTERN PetscErrorCode PetscLayoutSetLocalSize(PetscLayout,PetscInt);
PETSC_EXTERN PetscErrorCode PetscLayoutGetLocalSize(PetscLayout,PetscInt *);
PETSC_EXTERN PetscErrorCode PetscLayoutSetSize(PetscLayout,PetscInt);
PETSC_EXTERN PetscErrorCode PetscLayoutGetSize(PetscLayout,PetscInt *);
PETSC_EXTERN PetscErrorCode PetscLayoutSetBlockSize(PetscLayout,PetscInt);
PETSC_EXTERN PetscErrorCode PetscLayoutGetBlockSize(PetscLayout,PetscInt*);
PETSC_EXTERN PetscErrorCode PetscLayoutGetRange(PetscLayout,PetscInt *,PetscInt *);
PETSC_EXTERN PetscErrorCode PetscLayoutGetRanges(PetscLayout,const PetscInt *[]);
PETSC_EXTERN PetscErrorCode PetscLayoutCompare(PetscLayout,PetscLayout,PetscBool*);
PETSC_EXTERN PetscErrorCode PetscLayoutSetISLocalToGlobalMapping(PetscLayout,ISLocalToGlobalMapping);
PETSC_EXTERN PetscErrorCode PetscLayoutMapLocal(PetscLayout,PetscInt,const PetscInt[],PetscInt*,PetscInt**,PetscInt**);

PETSC_EXTERN PetscErrorCode PetscParallelSortInt(PetscLayout, PetscLayout, PetscInt*, PetscInt*);

PETSC_EXTERN PetscErrorCode ISGetLayout(IS,PetscLayout*);
PETSC_EXTERN PetscErrorCode ISSetLayout(IS,PetscLayout);

#endif