Pzgemv()

void Pzgemv	(	COMPLEX	alpha,
		COMPLEX **	A,
		int	ia,
		int	ni,
		int	ja,
		int	nj,
		COMPLEX *	x,
		COMPLEX	beta,
		COMPLEX *	y,
		COMPLEX *	z
	)

                       {

  int i,j;
  int* sendcounts;
  int* displs;
  int _start,_end;
  COMPLEX u[ia];
  COMPLEX _z[ia];


  sendcounts = calloc(size,sizeof(int));
  displs = calloc(size,sizeof(int));
  for(i=0;i<size;i++){
    calculate_bounds(i,ni,size, &_start,&_end);
    sendcounts[i] = _end-_start;
    displs[i] = _start;
  }


  for(i=0;i<ia;i++){
   u[i] = 0.0+I*0.0;
   for(j=0;j<nj;j++){
     u[i] += A[i][j]*x[j];
   }
  }



  if(NULL != y){
    for(i=0;i<ia;i++){ // WARNING
      _z[i] = alpha * u[i] + beta*y[i+displs[rank]];
    }
  }else{
    for(i=0;i<ia;i++){ // WARNING
      _z[i] = alpha * u[i];
    }
  }



  MPI_Allgatherv(_z,ia,MPI_ACOUSTO_COMPLEX,z,sendcounts,displs,MPI_ACOUSTO_COMPLEX,MPI_COMM_WORLD);


  free(sendcounts);
  free(displs);

}