Therefore, a compromisewas made. The six software
functions were divided into three groups, including (1) go to the
previous/next graphic; (2) zoom in/out; and (3) rotate clockwise/
counterclockwise by 90. Users were still allowed to determine the
sequence at will, such as 1-2-3 or 2-1-3, but could then easily
remember the sequence used on the previous interface. Thus,
deviations in measurement could be avoided.