Suppose I have several points on a two dimensional plot. Is there an online program (or open source or free tool) that can get the most accurate formula for my plotted points? Or if I were to do this in Excel, what is the easiest way to figure out the graphing formula? I actually have plots related to record counts in a star schema fact table versus disk space growth in SQL Server, and I want to predict how much growth there will be in the next 12 months. Our clustered index is causing our growth to be exponential, so that is the reason I want to figure out the formula. The quick sorts for this clustered index also has to be factored in. Sometimes a clustered index can take up more space than the data because of the quick sorts, and needs to be allocated as temporary, but available, disk space as part of this calculation. If we weren't using a clustered index, I'd just use a simple ratio.
As a test, use these points for an example. I will get the disk space for each later.
134,000,000 (Jan 2013) > 301,000,000 (May 2013) > 1,696,000,000 (Aug 2013)