reshape_down Subroutine

  subroutine reshape_down(cube, data, dim_cube, dim_data)
    !! Reshape the cube (\( 2^{nside} \)) into a grid with original dimension (opposite of reshape_up)
    implicit none

    real(xp), intent(in), dimension(:,:,:), allocatable :: cube !! original cube
    real(xp), intent(inout), dimension(:,:,:), allocatable :: data !! reshape cube
    integer, intent(in), dimension(3) :: dim_data !! original cube dimension
    integer, intent(in), dimension(3) :: dim_cube !! new cube dimension
 
    integer :: offset_w, offset_h
 
    offset_w = (dim_cube(2) - dim_data(2)) / 2
    offset_h = (dim_cube(3) - dim_data(3)) / 2
    data = cube(:, offset_w+1:offset_w+dim_data(2), offset_h+1:offset_h+dim_data(3)) 
  end subroutine reshape_down