package msj;
import mpi.*;
public class HelloWorld2 {
public static final int N = 10;
public static void main(String[] args) {
MPI.Init(args);
long startTime = System.currentTimeMillis();
int rank = MPI.COMM_WORLD.Rank();
int size = MPI.COMM_WORLD.Size();
int tag = 10, peer = (rank==0) ? 1:0;
if(rank == 0) {
double [][] a = new double [N][N];
for(int i = 0; i < N; i++)
for(int j = 0; j < N; j++)
a[i][j] = 10.0;
Object[] sendObjectArray = new Object[1];
sendObjectArray[0] = (Object) a;
MPI.COMM_WORLD.Send(sendObjectArray, 0, 1, MPI.OBJECT, peer, tag);
} else if(rank == 1){
double [][] b = new double [N][N];
for(int i = 0; i < N; i++)
for(int j = 0; j < N; i++)
b[i][j] = 0;
Object[] recvObjectArray = new Object[1];
MPI.COMM_WORLD.Recv(recvObjectArray, 0, 1, MPI.OBJECT, peer, tag);
b = (double[][]) recvObjectArray[0];
for(int i = 0; i < 4; i++){
for(int j = 0; j < N; i++)
//long endTime = System.currentTimeMillis();
//long endTime = System.currentTimeMillis();
System.out.print(b[i][j]+"\t");
System.out.println("\n");
//System.out.println("Calculated in " +
// (endTime - startTime) + " milliseconds");
}
}
MPI.Finalize() ;
}
}
我無法運行此程序。
當我在for循環中的變量之前未寫入int時,出現錯誤:for(int i = 0; i < N; i++)
。MPI Java矩陣乘法錯誤
問題與此有關嗎?
你有什麼想法,代碼沒有問題
你會得到什麼錯誤? –
java.lang.reflect.InvocationTargetException \t在sun.reflect.NativeMethodAccessorImpl.invoke0(本機方法) \t在sun.reflect.NativeMethodAccessorImpl.invoke(來源不明) \t在sun.reflect.DelegatingMethodAccessorImpl.invoke(來源不明) \t在java.lang.reflect.Method.invoke(來源不明) \t在runtime.starter.MulticoreStarter $ 1.run(MulticoreStarter.java:281) \t在java.lang.Thread.run(來源不明) 引起通過:java.lang.NullPointerException \t at msj.HelloWorld2.fillToken(HelloWorld2.java:272) \t at msj.HelloWorld2.main(HelloWorld2.java:40) \t ... 6更多 – drorhun