CODEWITHSUNDEEP
javampj-express
Jitka Darbie Hübnerová
Jitka Darbie Hübnerová

Reputation: 174

Where can I find some examples of using MPJ Express Library?

I have some java code, but searching for more (Pi, Integration, Brute Force MD5hash in Java, some other nice paralelism problem...). Thank you.

Upvotes: -1

Views: 2077

Answers (2)

bembas
bembas

Reputation: 771

If you are still intersting about examples i ve found a pi example in java (mpj) with the package p2pmpi.jar. It s really hard to find parralel source code in java the only solid examples is from mpj express unfortunately.

import p2pmpi.mpi.*;

public class Main {
    public static void main(String[] args) {
        int rank, size, i;
        double pi125dt = 3.141592653589793238462643;
        double h, sum, x;
        MPI.Init(args);
        size = MPI.COMM_WORLD.Size();
        rank = MPI.COMM_WORLD.Rank();
        int[] n = new int[1];
        double[] mypi = new double[1];
        double[] pi = new double[1];

        if (rank == 0)
            n[0] = 1000000; // number of intervals

        MPI.COMM_WORLD.Bcast(n, 0, 1, MPI.INT, 0);
        h = 1.0 / (double) n[0];
        sum = 0.0;
        for (i = rank + 1; i <= n[0]; i += size) {
            x = h * ((double) i - 0.5);
            sum += (4.0 / (1.0 + x * x));
        }
        mypi[0] = h * sum;
        MPI.COMM_WORLD.Reduce(mypi, 0, pi, 0, 1, MPI.DOUBLE, MPI.SUM, 0);
        if (rank == 0) {
            System.out.println("Po is approximately " + pi[0]);
            System.out.println("Error is :" + (pi[0] - pi125dt));
        }
        MPI.Finalize();
    }

}

Upvotes: 1

Ansar
Ansar

Reputation: 131

there are some generic example application provided with MPJ Express for testing and learning purposes. You can access them in MPJ_HOME\test\mpi directory. you may or may not get exactly the same applications you specified.

Upvotes: 2

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