Howdy, I built a webapp for myself that tracks my total portfolio and adjusts for estimated taxation. I did this because I got tired of the portfolio apps out there that would sum things like your 401k and your bank account as if they were the same dollars. These would incorrectly inflate the value of your porfolio and not acknowledge that a big part of that portfolio is Uncle Sam's. Almost 6 months ago, I added something that pushes various aggregated post-tax portfolio values into a history table so that I can graph the change in total value and various components of that total over time. This push happens about every other day. I then graph the results with various slices and dices using google's visualization api. That's all well and good, but do the math. I have many data points that are being plotted and it will only keep growing. I have tried a couple times to work out a way to "condense" the data set, but have thus far been unsuccessful. Imagine: Day Value 1 $20 2 $23 3 $25 4 $21 5 $19 6 $15 7 $19 8 $22 9 $23 ... I want to do one of two things. I would be fine with just sampling every nth row. The trouble is that I am using sqlite and have been unable to get this to work using their modulo operator. i.e.: Day Value 1 $20 4 $21 7 $19 ... The holy grail, though, would be to AVERAGE every nth row to output something like this: Start Day Value 1 $22.67 4 $18.33 7 $22.00 ... Any ideas? This definitely smells like something that will require a SQL formulation that will ultimately impress me in its complexity and/or creativity... -- Matt Warden Austin, TX, USA http://mattwarden.com This email proudly and graciously contributes to entropy.