Real variables are referred to in EARTH thus:
where LF stands for an integer. For example, the current-time pressure p at a particular cell in the grid might be stored in location 4782 of this array, thus:
4782 is then termed the "F-location index" (LF) of the current-time pressure at the point in question.
In order for PHOENICS users to access, and alter if need be, any variable stored in the array, they must know how to calculate the values of its LF. The present discussion is directed towards explaining how this is to be done.