fork download
copy 
  1. import mpi.MPI;
  2. import java.util.Arrays;
  3.  
  4. public class MPIAHCalculation {
  5.  
  6.     public static void main(String[] args) {
  7.         MPI.Init(args);
  8.  
  9.         int rank = MPI.COMM_WORLD.Rank();
  10.         int size = MPI.COMM_WORLD.Size();
  11.  
  12.         final int H = 100; // Assume H is predefined.
  13.         int[][] MX = new int[H][H];
  14.         int[][] MR = new int[H][H];
  15.         int[] Z = new int[H];
  16.         int[] C = new int[H];
  17.         int D = 0;
  18.  
  19.         if (rank == 0) {
  20.             // Initialize data in rank 0
  21.             MX = fillMatrix(H, H, 1);
  22.             MR = fillMatrix(H, H, 1);
  23.             Z = fillVector(H, 1);
  24.             C = fillVector(H, 1);
  25.             D = 5; // Example constant
  26.         }
  27.  
  28.         // Broadcast matrices and constants to all processes
  29.         for (int i = 0; i < H; i++) {
  30.             MPI.COMM_WORLD.Bcast(MX[i], 0, H, MPI.INT, 0);
  31.             MPI.COMM_WORLD.Bcast(MR[i], 0, H, MPI.INT, 0);
  32.         }
  33.         MPI.COMM_WORLD.Bcast(Z, 0, H, MPI.INT, 0);
  34.         MPI.COMM_WORLD.Bcast(C, 0, H, MPI.INT, 0);
  35.         MPI.COMM_WORLD.Bcast(new int[]{D}, 0, 1, MPI.INT, 0);
  36.  
  37.         // Divide work among processes
  38.         int rowsPerProcess = H / size;
  39.         int startRow = rank * rowsPerProcess;
  40.         int endRow = (rank == size - 1) ? H : startRow + rowsPerProcess;
  41.  
  42.         // Compute AH locally
  43.         int[] localAH = new int[endRow - startRow];
  44.         int c = Arrays.stream(C).min().orElse(Integer.MAX_VALUE);
  45.  
  46.         for (int i = startRow; i < endRow; i++) {
  47.             localAH[i - startRow] = c * Z[i] + D * matrixRowDot(MX, MR, i);
  48.         }
  49.  
  50.         // Gather results at rank 0
  51.         int[] AH = null;
  52.         if (rank == 0) {
  53.             AH = new int[H];
  54.         }
  55.         MPI.COMM_WORLD.Gather(localAH, 0, endRow - startRow, MPI.INT, AH, 0, rowsPerProcess, MPI.INT, 0);
  56.  
  57.         if (rank == 0) {
  58.             System.out.println("AH: " + Arrays.toString(AH));
  59.         }
  60.  
  61.         MPI.Finalize();
  62.     }
  63.  
  64.     // Utility method to fill a matrix with a specific value
  65.     public static int[][] fillMatrix(int rows, int cols, int value) {
  66.         int[][] matrix = new int[rows][cols];
  67.         for (int i = 0; i < rows; i++) {
  68.             Arrays.fill(matrix[i], value);
  69.         }
  70.         return matrix;
  71.     }
  72.  
  73.     // Utility method to fill a vector with a specific value
  74.     public static int[] fillVector(int size, int value) {
  75.         int[] vector = new int[size];
  76.         Arrays.fill(vector, value);
  77.         return vector;
  78.     }
  79.  
  80.     // Compute dot product of matrix row and vector
  81.     public static int matrixRowDot(int[][] matrix1, int[][] matrix2, int row) {
  82.         int sum = 0;
  83.         for (int i = 0; i < matrix1[row].length; i++) {
  84.             sum += matrix1[row][i] * matrix2[i][row]; // Adjusted dot product logic
  85.         }
  86.         return sum;
  87.     }
  88. }
  89.  
Success #stdin #stdout #stderr 0.3s 40772KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
Standard output is empty
stderr
copy 
Error: unexpected symbol in "import mpi.MPI"
Execution halted
https://ideone.com/7iw60B
language:
R (R 3.5.2)
created:
2 days ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!