do_internal_pressure - internal pressure gradient

INTERFACE:

    subroutine do_internal_pressure()

DESCRIPTION:

Here, the chosen internal pressure gradient method is selected and (in case that the compiler option SUBSTR_INI_PRESS is set), the initial pressure is calculated and subtracted from the updated internal pressure gradient.

If GETM is executed as slice model (compiler option SLICE_MODEL is set, the internal pressure gradient for $j=2$ is copied to $j=3$. USES:

    use getm_timers, only: tic, toc, TIM_INTPRESS
    IMPLICIT NONE

LOCAL VARIABLES:

    integer                :: i,j,k
    logical, save          :: first=.true.