MPI矩陣操作分兩部分：
1.讀文件
2.操作
讀文件的時候可以使用MPI_File_read來直接分配數據。
矩陣存儲的格式：連續內存空間，頭兩個int表示行列數，後續位置使用double表示數據，行優先存儲。
文件使用二進制方式直接存儲矩陣內存塊。
轉置非方陣，使用新申請的內存。如果使用O(1)的內存，並沒有規則的交換的過程，所以不大現實，邏輯太復雜，太慢。
[cpp]
#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;
}
#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;
}
