!-----------------------------------------------------------------------------------------------------------------------------------
! 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 gen_int_polynomial_fun_derivation_class
!! author: Stefan Mijin
!!
!! Houses derivation taking in multiple variables and performing a generalized integer powered polynomial calculation
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 ,IntArray ,RealArrayD2
use derivation_abstract_class ,only: Derivation
implicit none
private
type ,public ,extends(Derivation) :: GenIntPolyFunDeriv
!! Derivation taking in multiple variables and calculating multConst*fun(sum coef_i prod vars^powers) where prod vars^powers is
!! shorthand for a product of multiple variables raised to corresponding powers. Basically behaves like a multiplicative derivation where the
!! inner derivation is a massive sum of simple derivation outputs with integer powers. Implemented to allow AMJUEL rate fit derivations efficiently
type(IntArray) ,allocatable ,dimension(:) ,private :: polyPowers !! Variable powers for each monomial
real(rk) ,allocatable ,dimension(:) ,private :: polyCoeffs !! Polynomial coefficients for each monomial
real(rk) ,private :: multConst !! Constant coefficient - default 1
integer(ik) ,allocatable ,dimension(:) ,private :: maxPowers !! Maximum powers to be precalculated for each passed variable
character(:) ,allocatable ,private :: funcName !! Intrinsic function name optionally applied to polynomial
contains
procedure ,public :: init => initGenIntPolyFunDeriv
procedure ,public :: calculate => calculateGenIntPolyFun
end type GenIntPolyFunDeriv
!-----------------------------------------------------------------------------------------------------------------------------------
interface
!-----------------------------------------------------------------------------------------------------------------------------------
module subroutine initGenIntPolyFunDeriv(this,polyPowers,polyCoeffs,maxPowers,funcName,multConst)
!! Initialize generalized integer powered polynomial function derivation object
class(GenIntPolyFunDeriv) ,intent(inout) :: this
type(IntArray) ,dimension(:) ,intent(in) :: polyPowers
real(rk) ,dimension(:) ,intent(in) :: polyCoeffs
integer(ik) ,dimension(:) ,intent(in) :: maxPowers
character(*) ,optional ,intent(in) :: funcName
real(rk) ,optional ,intent(in) :: multConst
end subroutine initGenIntPolyFunDeriv
!-----------------------------------------------------------------------------------------------------------------------------------
module function calculateGenIntPolyFun(this,inputArray,indices) result(output)
class(GenIntPolyFunDeriv) ,intent(inout) :: this
type(RealArray) ,dimension(:) ,intent(in) :: inputArray
integer(ik) ,dimension(:) ,intent(in) :: indices
real(rk) ,allocatable ,dimension(:) :: output
end function calculateGenIntPolyFun
!-----------------------------------------------------------------------------------------------------------------------------------
end interface
!-----------------------------------------------------------------------------------------------------------------------------------
end module gen_int_polynomial_fun_derivation_class
!-----------------------------------------------------------------------------------------------------------------------------------
