public float at (final int r, final int c) throws MatrixException
  {
    if ((r < 0) || (r >= m_nRows) || (c < 0) || (c >= m_nCols))
    {
      throw new MatrixException (MatrixException.INVALID_INDEX);
    }

    return m_aValues[r][c];
  }
public float at ( final int r , final int c ) throws MatrixException { if ( ( r < 0 ) || ( r >= m_nRows ) || ( c < 0 ) || ( c >= m_nCols ) ) { throw new MatrixException ( MatrixException . INVALID_INDEX ) ; } return m_aValues [ r ] [ c ] ; }
Get the value of element [r,c] in the matrix.

@param r
the row index
@param c
the column index
@return the value
@throws MatrixException
for an invalid index