NAME
Gravity_unitTest
SYNOPSIS
call Gravity_unitTest()
integer(IN) :: fileUnit,
logical(OUT) :: perfect
DESCRIPTION
This function is the unit test for the Gravity unit. It is invoked in the setup unitTest/Gravity. The Config file for Gravity unit test setup requests an extra variable in the main grid data structure for storing the analytical solution
ARGUMENTS
fileUnit : unit number for file opened by the unitTest/Gravity setup
in which to write results of the test
perfect : indicates test ran without error is true.
PARAMETERS
eintSwitch a rarely used switch which ensures that internal energy calculations
maintain sufficient precision. Important only if energyTotal is dominated
by energyKinetic.