code: public int[] getIC()
      {
          int[] ic = new int[nzmax];
          int i = 0;
          for ( IndexMN index : indexSet )
          {
              ic[i++] = index.n;
          }
          return ic;
      }
docs: Gets column indices
  
  <tt>ic</tt> points to an integer array of length nzmax containing the column indices of
  the corresponding elements in <tt>pr</tt> and <tt>pi</tt>.