Published online by Cambridge University Press: 28 July 2016
In the analytical presentation of curves the main requirements perhaps are those of accuracy and simplicity and the problem confronting the engineer is the efficient combination of the two. A further important consideration is that of the range over which the empirical formula (or formulae in some cases) is to be effective, for clearly the greater this range is, the more useful will be the formula.
It is obviously desirable that any equation that is chosen should be as close a fit as possible to the practical curve. It must not be sensitive to small parametric differences and it should be possible to determine these parameters with a fair degree of precision.