Regardless of the type of graph, it's important to understand whether a difference of 5 units between one measure and the next is meaningful. For example if yo

Regardless of the type of graph, it's important to understand whether a difference of 5 units between one measure and the next is meaningful. For example if you are measuring the length of optical fibre and the difference between the lengths of fibres is 5cm over 100km, is that important in the context? You'll already lose several metres of length in various loops and coils that are important for reliable function of that 100km length of fibre. On the other hand when cutting frames for doors, the difference of a couple of millimetres over the two metre length of the side of the frame can make the difference between passing or failing the building envelope pressurisation test. On the gripping hand when I'm shooting an arrow 50m to a target, what's of interest to me is not the distance from me to the arrow but the tiny variances in distance from the arrow to the bullseye. So measuring the vector from me to the arrow is pointless and the centimetre or two difference in length of those vectors is meaningless.