!-----------------------------------------------------------------------------------------------------------------------------------
! This file is part of ReMKiT1D.
!
! ReMKiT1D is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as
! published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
!
! ReMKiT1D is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
! MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
!
! You should have received a copy of the GNU General Public License along with ReMKiT1D. If not, see <https://www.gnu.org/licenses/>.
!
! Copyright 2023 United Kingdom Atomic Energy Authority (stefan.mijin@ukaea.uk)
!-----------------------------------------------------------------------------------------------------------------------------------
module moment_derivation_class
!! author: Stefan Mijin
!!
!! Houses moment derivation class handling derivations of the form const*product(fluidVariables**powers)* m-th moment of h-th
!! harmonic of f * g, where g is an optional constant velocity vector
use data_kinds ,only: rk ,ik
use runtime_constants ,only: debugging, assertions, assertionLvl
use assertion_utility ,only: assert, assertIdentical, assertPure
use god_objects ,only: Object
use support_types ,only: RealArray
use derivation_abstract_class ,only: Derivation
use v_space_class ,only: VSpace
implicit none
private
type ,public ,extends(Derivation) :: MomentDerivation
!! Moment derivation object. First step in derivation is taking the mOrder-th moment of the h-th harmonic of the first passed
!! variable (assumes that it is a distribution), optionally multiplied by constant velocity space vector g. The results is then
!! optionally multiplied by a constant and a product of fluid variables raised to powers (as in SimpleDerivation).
real(rk) ,allocatable ,dimension(:) ,private :: varPowers !! Powers corresponding to each fluid variable - indices in calculate must conform size of this + 1
real(rk) ,private :: multConst !! Multiplicative constant - default 1
integer(ik) ,private :: mOrder !! Moment order
integer(ik) ,private :: h !! Harmonic to take moment of
real(rk) ,allocatable ,dimension(:) ,private :: g !! Optional velocity space vector
type(VSpace) ,private :: vSpaceCopy !! Copy of velocity space object used to take the moment
!! (NOTE: this might cause performance issues if many momentDerivations are present at once)
contains
procedure ,public :: init => initMomentDeriv
procedure ,public :: calculate => calculateMomentDeriv
end type MomentDerivation
!-----------------------------------------------------------------------------------------------------------------------------------
interface
!-----------------------------------------------------------------------------------------------------------------------------------
module subroutine initMomentDeriv(this,mOrder,h,refVSpace,varPowers,g,multConst)
!! Initialize moment derivation object
class(MomentDerivation) ,intent(inout) :: this
integer(ik) ,intent(in) :: mOrder !! Moment order
integer(ik) ,intent(in) :: h !! Harmonic to take moment of
type(VSpace) ,intent(in) :: refVSpace !! Velocity space object to make copy of
real(rk) ,optional ,dimension(:) ,intent(in) :: varPowers !! Optional fluid variable powers
real(rk) ,optional ,dimension(:) ,intent(in) :: g !! Optional velocity space vector
real(rk) ,optional ,intent(in) :: multConst !! Optional multiplicative constant - default 1
end subroutine initMomentDeriv
!-----------------------------------------------------------------------------------------------------------------------------------
module function calculateMomentDeriv(this,inputArray,indices) result(output)
class(MomentDerivation) ,intent(inout) :: this
type(RealArray) ,dimension(:) ,intent(in) :: inputArray
integer(ik) ,dimension(:) ,intent(in) :: indices
real(rk) ,allocatable ,dimension(:) :: output
end function calculateMomentDeriv
!-----------------------------------------------------------------------------------------------------------------------------------
end interface
!-----------------------------------------------------------------------------------------------------------------------------------
end module moment_derivation_class
!-----------------------------------------------------------------------------------------------------------------------------------
