matrix7

//http://blog.csdn.net/pouloghost/article/details/8824089#include <stdio.h>  #include <stdlib.h>  #include "mpi.h"    /* matrix transpostion using mpi  linear division author GT 2013.4.18 */  int rank,size;  /* file is in binary form initial two int are size afterwards is double data all matrix is in the same form */  /* read the size of @fileName return in @sizes  */  void readSize(char *fileName, int* sizes)  {      FILE *in;      in = fopen(fileName, "rb");      if(in == NULL)      {          return ;      }      fread(sizes, sizeof(int), 2, in);      fclose(in);  }  /* divide the matrix columns averagely among all threads while reading the @fileName the matrix is @row*@col return in @dest  */  void readMatrixByColumn (char *fileName, int row, int col, double *dest)  {      //amazingly simple function to averagely divide array      //[colStart,colEnd)      int colStart = rank * col / size;      int colEnd = (rank + 1) * col / size;       int myCol = colEnd - colStart;      //columns for a thread       MPI_Datatype columns;       MPI_Type_vector (row, myCol, col, MPI_DOUBLE, &columns);      MPI_Type_commit(&columns);      //file operation      MPI_File file;      MPI_Status status;      MPI_File_open (MPI_COMM_WORLD, fileName, MPI_MODE_CREATE | MPI_MODE_RDWR, MPI_INFO_NULL, &file);      //current start position      MPI_Offset offset = colStart * sizeof(double) + 2 * sizeof(int);      //read      MPI_File_set_view (file, offset, MPI_DOUBLE, columns, "native", MPI_INFO_NULL);      MPI_File_seek (file, 0, MPI_SEEK_SET);      double *data = (double*)((int*)dest + 2);      MPI_File_read (file, data, myCol * row, MPI_DOUBLE, &status);      //set coordinate      *((int*) dest) = row;      *((int*) dest + 1) = myCol;      //clean up      MPI_File_close (&file);      MPI_Type_free (&columns);  }          /* convert 1d index @one into 2d coordinate @xy  the matrix is row*@col */  extern inline void one2two (int one, int col,int *xy)  {      xy[0] = one / col;      xy[1] = one % col;  }  /* convert using two ints */  extern inline int two2one3 (int x, int y, int col)  {      return x * col + y;  }    /* convert 2d @xy into 1d @return  matrix is row * @col */  extern inline int two2one2 (int *xy, int col)  {      return two2one3 (xy[0], xy[1], col);  }  /* transposition 2d @xy to 1d @return */  extern inline int transpositionTwo2one (int *xy, int row)  {      return two2one3 (xy[1], xy[0], row);  }  /* transposite @matrix and store in @tran */    void transposite (double *matrix, double *tran)  {      int row = *((int*) matrix);      int col = *((int*) matrix + 1);      *((int*) tran) = col;      *((int*) tran + 1) = row;      int xy[2];      double *matrixData = (double*) ((int*) matrix + 2);      double *tranData = (double*) ((int*) tran + 2);      for ( int i = 0; i < row * col; ++ i )      {          one2two ( i, col, xy );          *(tranData + transpositionTwo2one (xy, row)) = *(matrixData + i);         }  }    void show (double *matrix)  {      double *data =(double*) ((int*) matrix + 2);      int row = *((int*) matrix);      int col = *((int*) matrix + 1);      printf ("%d %d matrix \n", row, col);      for (int i = 0; i < row; ++i)      {          for (int j = 0; j < col; ++j)          {              printf("%lf ",*(data + i * col + j));          }          printf("\n");      }  }  void testRead (char *fileName, int *sizes)  {      int err;      MPI_File file;      MPI_Status status;      MPI_File_open (MPI_COMM_WORLD, fileName, MPI_MODE_CREATE | MPI_MODE_RDWR, MPI_INFO_NULL, &file);      MPI_File_set_view (file, 0, MPI_INT, MPI_INT, "native", MPI_INFO_NULL);      if(0 == rank)          printf("e %d %d %d \n", err, sizes[0], sizes[1] );      err = MPI_File_read (file, sizes, 2, MPI_INT, &status);      if(0 == rank)          printf("ee %d %d %d \n", err, sizes[0], sizes[1] );      MPI_File_close (&file);  }  int main (int argc, char* argv[])  {      MPI_Init (&argc, &argv);      MPI_Comm_rank (MPI_COMM_WORLD, &rank);      MPI_Comm_size (MPI_COMM_WORLD, &size);        int sizes[2];      readSize (argv[1], sizes);      double *matrix = (double*) malloc(sizes[0] * sizes[1] * sizeof(double) + 2 *sizeof(int));      double *transp = (double*) malloc(sizes[0] * sizes[1] * sizeof(double) + 2 *sizeof(int));      readMatrixByColumn (argv[1], sizes[0], sizes[1], matrix);      transposite(matrix ,transp);      if (2 == rank)      {          printf ("matrix\n");          show (matrix);          printf ("transposition \n");          show (transp);      }      MPI_Finalize ();      free (matrix);      return 0;  }