corecel/grid/UniformGridData.hh

0001 //------------------------------- -*- C++ -*- -------------------------------//
0002 // Copyright Celeritas contributors: see top-level COPYRIGHT file for details
0003 // SPDX-License-Identifier: (Apache-2.0 OR MIT)
0004 //---------------------------------------------------------------------------//
0005 //! \file corecel/grid/UniformGridData.hh
0006 //---------------------------------------------------------------------------//
0007 #pragma once
0008
0009 #include "corecel/Assert.hh"
0010 #include "corecel/Types.hh"
0011 #include "corecel/cont/EnumArray.hh"
0012 #include "corecel/data/Collection.hh"
0013
0014 #include "GridTypes.hh"
0015
0016 namespace celeritas
0017 {
0018 //---------------------------------------------------------------------------//
0019 /*!
0020  * Data input for a uniform increasing grid.
0021  *
0022  * The four parameters are overconstrained -- we could omit back by calculating
0023  * from the front, delta, and size. In practice, though, that can introduce an
0024  * inconsistency into the "find" function.
0025  */
0026 struct UniformGridData
0027 {
0028     using value_type = ::celeritas::real_type;
0029
0030     size_type size{};  //!< Number of grid edges/points
0031     value_type front{};  //!< Value of first grid point
0032     value_type back{};  //!< Value of last grid point
0033     value_type delta{};  //!< Grid cell width
0034
0035     //! True if assigned and valid
0036     CELER_FUNCTION operator bool() const
0037     {
0038         return size >= 2 && delta > 0 && front < back;
0039     }
0040
0041     //// HELPER FUNCTIONS ////
0042
0043     // Construct on host from front/back
0044     inline static UniformGridData
0045     from_bounds(EnumArray<Bound, double> bounds, size_type size);
0046 };
0047
0048 //---------------------------------------------------------------------------//
0049 /*!
0050  * Parameterization of a discrete scalar field on a given 1D grid.
0051  *
0052  * \c derivative stores the second derivative of the interpolating cubic
0053  * spline. If it is non-empty, cubic spline interpolation will be used.
0054  *
0055  * \c spline_order stores the order of the piecewise polynomials used for
0056  * spline interpolation without continuous derivatives. The order must be
0057  * smaller than the grid size for effective spline interpolation. If the order
0058  * is set to 1, linear or cubic spline interpolation will be used.
0059  */
0060 struct UniformGridRecord
0061 {
0062     UniformGridData grid;
0063     ItemRange<real_type> value;
0064     ItemRange<real_type> derivative;
0065     size_type spline_order{1};
0066
0067     //! Whether the record is initialized and valid
0068     explicit CELER_FUNCTION operator bool() const
0069     {
0070         return grid && grid.size == value.size()
0071                && (derivative.empty() || grid.size == derivative.size())
0072                && spline_order > 0 && spline_order < value.size()
0073                && (derivative.empty() || spline_order == 1);
0074     }
0075 };
0076
0077 //---------------------------------------------------------------------------//
0078 /*!
0079  * Construct from min/max and number of grid points.
0080  */
0081 UniformGridData
0082 UniformGridData::from_bounds(EnumArray<Bound, double> bounds, size_type size)
0083 {
0084     CELER_EXPECT(size >= 2);
0085     CELER_EXPECT(bounds[Bound::lo] < bounds[Bound::hi]);
0086     UniformGridData result;
0087     result.size = size;
0088     result.front = bounds[Bound::lo];
0089     result.back = bounds[Bound::hi];
0090     result.delta = (bounds[Bound::hi] - bounds[Bound::lo]) / (size - 1);
0091     CELER_ENSURE(result);
0092     return result;
0093 }
0094
0095 //---------------------------------------------------------------------------//
0096 }  // namespace celeritas