text: Elasticities coefficient can also be computed numerically, something that is often done in simulation software.
  For example, a small change (say 5%) can be made to the chosen reactant concentration, and the change in the reaction rate recorded. To illustrate this, assume that the reference reaction rate is , and the reference reactant concentration, . If we increase the reactant concentration by  and record the new reaction rate as , then the elasticity can be estimated by using Newton's difference quotient:
  A much better estimate for the elasticity can be obtained by doing two separate perturbations in . One perturbation to increase  and another to decrease . In each case, the new reaction rate is recorded; this is called the two-point estimation method. For example, if  is the reaction rate
  when we increase , and  is the reaction rate when we decrease , then
  we can use the following two-point formula to estimate the elasticity: