go_up_level Subroutine

  subroutine go_up_level(cube_params)
    !! Projection of the solution at next level (nside += 1)
    implicit none

    real(xp), intent(inout), dimension(:,:,:), allocatable :: cube_params !! cube of parameters

    integer :: i, j, k, l
    real(xp), dimension(:,:,:), allocatable :: cube_params_down 
    integer, dimension(3) :: dim

    dim = shape(cube_params)
    allocate(cube_params_down(dim(1), dim(2), dim(3)))
    cube_params_down = 0._xp
    
    cube_params_down = cube_params
    
    deallocate(cube_params)
    allocate(cube_params(dim(1),dim(2)*2, dim(3)*2))
    cube_params = 0._xp
    
    do i=1,size(cube_params_down,dim=2)
       do j=1,size(cube_params_down,dim=3)
          do k=1,2
             do l=1,2
                cube_params(:,k+((i-1)*2),l+((j-1)*2)) = cube_params_down(:,i,j)
             enddo
          enddo
       enddo
    enddo
    
  end subroutine go_up_level