Line data    Source code

       1            0 : // Distributed under the MIT License.
       2              : // See LICENSE.txt for details.
       3              : 
       4              : #pragma once
       5              : 
       6              : #include <cstddef>
       7              : 
       8              : #include "DataStructures/DataVector.hpp"
       9              : #include "Utilities/Gsl.hpp"
      10              : 
      11              : namespace ylm {
      12              : /// @{
      13              : /*!
      14              :  * \ingroup SpectralGroup
      15              :  *
      16              :  * \brief Evaluates a real spherical harmonic of order l at the requested
      17              :  * angles \f$\theta\f$ and \f$\phi\f$.
      18              :  *
      19              :  * The real spherical harmonics are defined as:
      20              :  * \begin{equation}
      21              :  * Y_{lm}(\theta, \phi) =
      22              :  * \begin{cases}
      23              :  * \sqrt{2} (-1)^m \mathcal{I}[Y_l^{|m|}] & \text{if } m < 0 \\
      24              :  *  Y_l^{0} & \text{if } m = 0 \\
      25              :  * \sqrt{2} (-1)^m \mathcal{R}[Y_l^{m}] & \text{if } m > 0
      26              :  * \end{cases}
      27              :  * \end{equation}
      28              :  *
      29              :  * where \f$Y_l^m\f$ are the complex spherical harmonics and \f$\mathcal{R}\f$
      30              :  * denotes the real part and \f$\mathcal{I}\f$ denotes the imaginary part.
      31              :  *
      32              :  * \note This implementation uses the boost implementation of spherical
      33              :  * harmonics. The calculation is not vectorized and may be slow.
      34              :  * Stability has not been tested for large l.
      35              :  */
      36            1 : void real_spherical_harmonic(gsl::not_null<DataVector*> spherical_harmonic,
      37              :                              const DataVector& theta, const DataVector& phi,
      38              :                              size_t l, int m);
      39              : 
      40            1 : DataVector real_spherical_harmonic(const DataVector& theta,
      41              :                                    const DataVector& phi, size_t l, int m);
      42              : /// @}
      43              : }  // namespace ylm