Re: [GENERAL] Calculating a moving average

[Dann Corbit]

Title: Message

Why not use a cursor?   P.S. A moving average will look much better if you Hahn the tails. To do a normal 7 point moving average, you take (x[i]+ x[i+1]+ x[i+2]+ x[i+3]+ x[i+4]+ x[i+5]+ x[i+6])/7 as point xprime[i] and (y[i]+ y[i+1]+ y[i+2]+ y[i+3]+ y[i+4]+ y[i+5]+ y[i+6])/7 as point yprime[i].   But when you start let x[0], y[0] be the first point, and then average the next 2 for the second point… until you get to 7 and then do the same thing in the other end.  Otherwise, you get a very strange looking curve.   IMO-YMMV From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Vanole, Mike Sent: Wednesday, January 19, 2005 1:34 PM To: pgsql-general@postgresql.org Subject: [GENERAL] Calculating a moving average   Hi,   I need to calculate a moving average and I would like to do it with SQL, or a Pg function built for this purpose. I'm on Pg 7.4. Is this possible in Pg without a bunch of self joins, or is there a funtion available?   Thanks, Mike