deriv_1d_unit Subroutine

private pure subroutine deriv_1d_unit(g, dg)

Matching high-order first derivative of a unit-spacing nodal line: the undivided difference of the conservative-flux face values (cons_flux_1d_unit), so dg(i) reproduces the high-order central derivative AND stays bit-consistent with the face metrics built from the same operator (the property that makes freestream telescope to round-off, design spec ยง5.3).

Arguments

Type IntentOptional Attributes Name
real(kind=wp), intent(in) :: g(:)
real(kind=wp), intent(out) :: dg(:)