MPI Matrix Multiplication (C Code)

Message Passing interface is largely used for work done in parallel computers. Other than using a Serial program, using MPI will increase the processing speed.

In the given example two N * N matrix will be multiplied and given the output matrix.

You can Download Code From HERE

Execute the code using following commands

To Compile 
[aruna@ubuntu]~$ mpicc -o matrix matrix.c

To Run the Code
[aruna@ubuntu]~$ mpirun -np 4 matrix 
(here -np argument means the number of workers that we are going to use)

/**********************************************************************

 Message Parsing Interface (MPI) Matrix Multiplication A*B = C
 
*********************************************************************/

#include "stdio.h"
#include "mpi.h"
#define N    500        /* number of rows and columns in matrix */

MPI_Status status;

double a[N][N],b[N][N],c[N][N];  //matrix used 
       
main(int argc, char **argv){
 struct timeval start, stop;
 int numberOfTasks,
 mtype,
 taskID,
 numberOfWorkers,
 source,
 destination,
 rows,
 averageRow,
 extra,
 offset,i,j,k;
 //first initialization
 MPI_Init(&argc, &argv);
 MPI_Comm_rank(MPI_COMM_WORLD, &taskID);
 MPI_Comm_size(MPI_COMM_WORLD, &numberOfTasks);

 numberOfWorkers = numberOfTasks-1;

 //---------------------------- master ----------------------------//
 if (taskID == 0) {
   for (i=0; i<N; i++) {
      for (j=0; j<N; j++) {   
  a[i][j]= 1.0;
  b[i][j]= 2.0;
     }
          }

    /* send matrix data to the worker tasks */
 
   gettimeofday(&start, 0);
 
          averageRow = N/numberOfWorkers; //average rows per worker
   extra= N%numberOfWorkers;  //extra rows
          offset = 0;
    
          for (destination=1; destination<=numberOfWorkers; destination++){       
 
     if(destination<=extra){
        rows = averageRow+1;
     }else{
        rows = averageRow;
     }
     mtype = 1;
     MPI_Send(&offset, 1, MPI_INT, destination, mtype, MPI_COMM_WORLD);
     MPI_Send(&rows, 1, MPI_INT, destination, mtype, MPI_COMM_WORLD);
     MPI_Send(&a[offset][0], rows*N, MPI_DOUBLE,destination,mtype, MPI_COMM_WORLD);
     MPI_Send(&b, N*N, MPI_DOUBLE, destination, mtype, MPI_COMM_WORLD);
     offset = offset + rows;
  }

    /* wait for results from all worker tasks */
  for (i=1; i<=numberOfWorkers; i++){
     mtype = 2;
     source = i;
     MPI_Recv(&offset, 1, MPI_INT, source, mtype, MPI_COMM_WORLD, &status);
     MPI_Recv(&rows, 1, MPI_INT, source, mtype, MPI_COMM_WORLD, &status);
     MPI_Recv(&c[offset][0], rows*N, MPI_DOUBLE, source, mtype, MPI_COMM_WORLD, &status);
  }
  gettimeofday(&stop, 0);
 
  
  printf("Upper Left = %6.2f    Upper Right = %6.2f \n",c[0][0],c[0][N-1]);
  printf("Lower Left = %6.2f    Lower Right = %6.2f \n",c[N-1][0],c[N-1][N-1]);
  
  fprintf(stdout,"Time = %.6f\n\n",(stop.tv_sec+stop.tv_usec*1e-6)-(start.tv_sec+start.tv_usec*1e-6));

 
 } 

  /*---------------------------- worker----------------------------*/
 if (taskID > 0) {
     source = 0;
     mtype = 1;
     MPI_Recv(&offset, 1, MPI_INT, source, mtype, MPI_COMM_WORLD, &status);
     MPI_Recv(&rows, 1, MPI_INT, source, mtype, MPI_COMM_WORLD, &status);
     MPI_Recv(&a, rows*N, MPI_DOUBLE, source, mtype, MPI_COMM_WORLD, &status);
     MPI_Recv(&b, N*N, MPI_DOUBLE, source, mtype, MPI_COMM_WORLD, &status);
  
    /* Matrix multiplication */
     for (k=0; k<N; k++)
   for (i=0; i<rows; i++) {
            c[i][k] = 0.0;
     for (j=0; j<N; j++)
   c[i][k] = c[i][k] + a[i][j] * b[j][k];
         }

     mtype = 2;
     MPI_Send(&offset, 1, MPI_INT, 0, mtype, MPI_COMM_WORLD);
     MPI_Send(&rows, 1, MPI_INT, 0, mtype, MPI_COMM_WORLD);
     MPI_Send(&c, rows*N, MPI_DOUBLE, 0, mtype, MPI_COMM_WORLD);
 }  
    
  MPI_Finalize();
} 

By the way to prepare the running environment please refer this site.. http://www.lam-mpi.org/
If you have anything to clarify. Please Drop a comment.. :)

How to build a fat jar using Netbeans

Hmm after long time with out blogging. Finally decided to add some posts to my blog. So in this post I would like to describe how to build a fat jar using NetBeans. Of course you can simply do it using Eclipse. But in Netbeans you can't actually directly build a fat jar. The jar which is build using NetBeans is not adding the libraries you've used for the project. The libraries are added to a folder called "lib" whenever you run the jar the "lib" folder must be in the same directory.

So lets get started building a fat jar using Netbeans. The first thing you have to do is clean and build the project.

Then go the Files view of the Project and open the build.xml file.

Then copy and paste the following code just before the " project" tag ends.

Download file from here DOWNLOAD FILE

Then it's almost done. Now in files view of the project right click build.xml file and then select Runtarget >> Other Targets >> package-for-store.

That's it now your fat jar has been created. Go to your project folder and check the folder called store. Inside that folder you can see your fat jar.

That's it now you know how to build a fat jar using NetBeans. If you need any help just put a comment. Cheers :)