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Exercise 11

Write a program working only with 2 MPI processes.

For each process, define a square matrix A (nXn). Rank 0 fills the matrix with 0, while rank 1 fills it with 1. Define a datatype that handles a column (if C) or a row (If Fortran) of A.

Extract size and extent of this type: is the result what you expect?

Now begin the communication: rank 0 sends the first column/row of A to rank 1, overwriting its own first column/row. Check the results by printing the matrix on the screen.Modify the code by sending the first nb columns/rows of A: do you have to change the type? Can you send two items of the new type?

	C
MPI_TYPE_VECTOR	`int MPI_Type_vector(int count, int blocklength, int stride, MPI_Datatype oldtype, MPI_Datatype *newtype)`
MPI_TYPE_COMMIT	`int MPI_Type_commit(MPI_Datatype *datatype)`
MPI_TYPE_FREE	`int MPI_Type_free(MPI_Datatype *datatype)`
MPI_TYPE_SIZE	`int MPI_Type_size(MPI_Datatype datatype, int size)`
MPI_TYPE_GET_EXTENT	`int MPI_Type_get_extent(MPI_Datatype datatype, MPI_Aint lb, MPI_Aint *extent)`
MPI_SEND	`int MPI_Send(void* buf, int count, MPI_Datatype datatype, int dest, int tag, MPI_Comm comm)`
MPI_RECV	`int MPI_Recv(void* buf, int count, MPI_Datatype datatype, int source, int tag, MPI_Comm comm, MPI_Status *status)`
MPI_INIT	`int MPI_Init(int argc, char **argv)`
MPI_COMM_SIZE	`int MPI_Comm_size(MPI_Comm comm, int *size)`
MPI_COMM_RANK	`int MPI_Comm_rank(MPI_Comm comm, int *rank)`
MPI_FINALIZE	`int MPI_Finalize(void)`
	FORTRAN
MPI_TYPE_VECTOR	`MPI_TYPE_VECTOR(COUNT, BLOCKLENGTH, STRIDE, OLDTYPE, NEWTYPE, IERROR) INTEGER COUNT, BLOCKLENGTH, STRIDE, OLDTYPE, NEWTYPE, IERROR`
MPI_TYPE_COMMIT	`MPI_TYPE_COMMIT(DATATYPE, IERROR) INTEGER DATATYPE, IERROR`
MPI_TYPE_FREE	`MPI_TYPE_FREE(DATATYPE, IERROR) INTEGER DATATYPE, IERROR`
MPI_TYPE_SIZE	`MPI_TYPE_SIZE(DATATYPE, SIZE, IERROR) INTEGER DATATYPE, SIZE, IERROR`
MPI_TYPE_GET_EXTENT	`MPI_TYPE_GET_EXTENT(DATATYPE, LB, EXTENT, IERROR) INTEGER DATATYPE, IERROR INTEGER (KIND=MPI_ADDRESS_KIND) LB, EXTENT`
MPI_SEND	`MPI_SEND(BUF, COUNT, DATATYPE, DEST, TAG, COMM, IERROR) <type> BUF(*) INTEGER COUNT, DATATYPE, DEST, TAG, COMM, IERROR`
MPI_RECV	`MPI_RECV(BUF, COUNT, DATATYPE, SOURCE, TAG, COMM, STATUS, IERROR) <type> BUF(*) INTEGER COUNT, DATATYPE, SOURCE, TAG, COMM, STATUS(MPI_STATUS_SIZE), IERROR`
MPI_INIT	`MPI_INIT(IERROR) INTEGER IERROR`
MPI_COMM_SIZE	`MPI_COMM_SIZE(COMM, SIZE, IERROR) INTEGER COMM, SIZE, IERROR`
MPI_COMM_RANK	`MPI_COMM_RANK(COMM, RANK, IERROR) INTEGER COMM, RANK, IERROR`
MPI_FINALIZE	`MPI_FINALIZE(IERROR) INTEGER IERROR`