void
_do_matrix( char *in, long rows, long cols, char *out )
CODE:
  long i, j, a;
  double *in_matrix= (double *)in;
  double *out_matrix= (double *)out;
  double value;

  for(  i= 0;  i < rows;  i++  ) {
    for(  j= i-1;  j >= 0;  j--  ) {
      value= 0;
      for(  a= 0;  a <= cols;  a++  ) {
        value += in_matri­x[i*cols+a]*in_matrix[j*cols+a];
      }
      value /= (cols-1);
      out_matrix[i*rows+j]= val­ue;
    }
  }