\brief Computes the inverse square root of the matrix. * * \returns the inverse positive-definite square root of the matrix *

\brief Computes the positive-definite square root of the matrix. * * \returns the positive-definite square root of the matrix *

\returns an expression of the opposite of \c *this */

\returns a non const expression of the imaginary part of \c *this. * * \sa real() */

\returns a non const expression of the real part of \c *this. * * \sa imag() */