Line data    Source code

       1            0 : // Distributed under the MIT License.
       2              : // See LICENSE.txt for details.
       3              : 
       4              : #pragma once
       5              : 
       6              : #include <utility>
       7              : 
       8              : namespace ScalarTensor {
       9              : /// @{
      10              : /*!
      11              :  * \brief Function to smoothly turn on the coupling terms.
      12              :  *
      13              :  * \details Implements Eq. B4 of \cite Okounkova:2019zjf :
      14              :  * \begin{align}
      15              :  *    t_*  &\equiv (t - t_\mathrm{s})/t_\mathrm{ramp} \,, \\
      16              :  *    F(t) &= t_*^5  (126 + t_* (-420 + t_* (540 + t_* (-315 + 70 t_*))))~,
      17              :  * \end{align}
      18              :  * where $ t_\mathrm{s} $ and $ t_\mathrm{ramp} $ are parameters that
      19              :  * control the start time and duration of the turn-on period.
      20              :  * Note that $F(t)$ is `smoothstep<4>`.
      21              :  */
      22            1 : double nonic_ramp_function(double time, double start_time, double ramp_time);
      23              : 
      24            1 : double nonic_ramp_function(double time,
      25              :                              std::pair<double, double> start_and_ramp_times);
      26              : /// @}
      27              : }  // namespace ScalarTensor