RDF - Price Elasticity Measures

In the forecasting process when RDF sees a regular price change, we know that it applies an elasticity value, decay factor and effective periods. In order to determine these values, we need to analyse our historical data (this has got nothing to do with the data in RDF now - it could be in excel). In order to arrive at the correct value for elasticity, it would be helpful to know how RDF applies the regular price change calculation over a period of time so that the value in the measure is appropriate. We can measure elasticity at a point