Gabor, Thank you for your help -- it did help me a lot. However, with my data:
lead_time cycle r_squared fcst_date 1 6 0 5.405095e-02 07/31/2010 2 12 0 5.521620e-06 07/31/2010 3 18 0 1.565910e-04 07/31/2010 4 24 0 8.646822e-02 07/31/2010 5 30 0 1.719604e-02 07/31/2010 6 36 0 5.768113e-04 07/31/2010 7 42 0 2.501269e-06 07/31/2010 8 48 0 6.451727e-02 07/31/2010 9 6 12 2.857931e-01 07/31/2010 10 12 12 1.138635e-01 07/31/2010 11 18 12 2.225503e-02 07/31/2010 12 24 12 1.182031e-03 07/31/2010 13 30 12 8.841142e-04 07/31/2010 14 36 12 1.082490e-01 07/31/2010 15 42 12 1.502887e-05 07/31/2010 17 6 0 8.689588e-02 08/01/2010 18 12 0 5.884336e-04 08/01/2010 19 18 0 2.219316e-07 08/01/2010 20 24 0 3.960752e-02 08/01/2010 21 30 0 1.087413e-04 08/01/2010 23 42 0 3.583030e-07 08/01/2010 24 48 0 2.907109e-05 08/01/2010 25 6 12 8.693451e-02 08/01/2010 26 12 12 3.208215e-02 08/01/2010 27 18 12 0.000000e+00 08/01/2010 28 6 0 2.962669e-02 08/02/2010 29 6 12 2.363506e-05 08/02/2010 30 12 12 9.050178e-03 08/02/2010 from: > z <- read.zoo(q,index = 4, FUN = as.yearmon, format = "%m/%d/%Y",aggregate = mean) I get: > z lead_time cycle r_squared Jul 2010 25.60000 5.600000 0.05034771 Aug 2010 18.46154 4.615385 0.02191903 what I need is to NOT have the lead_time and cycle averaged, but only have the r_squared values averaged by lead_time and cycle. I can not seem to figure out the correct syntax to do this. I assume I use something like: q_agg<-aggregate(q,by=list(q$lead_time,q$cycle),index = 4, FUN = as.yearmon, format = "%m/%d/%Y") but I get errors or nonsense when I follow with... z <- read.zoo(q_agg,index = 4, FUN = as.yearmon, format = "%m/%d/%Y",aggregate = mean) or some variation of this. Regards, Tom On Sat, Mar 24, 2012 at 10:58 PM, Gabor Grothendieck < ggrothendi...@gmail.com> wrote: > On Sat, Mar 24, 2012 at 10:44 PM, Thomas Adams <thomas.ad...@noaa.gov> > wrote: > > All: > > > > I have a SQlite database where I have stored some verification data by > date > > & time (cycle Z/UTC), lead_time as well as type, duration, etc. I would > > like to analyze & plot the data as monthly averages. I have looked at a > > bunch of examples which use some combination of zoo and aggregate, but I > > have not been able to successfully apply bits and pieces from the > examples > > I have found. Any help is appreciated. BTW, I calculate mae (mean > absolute > > error), mse (mean squared error), me (mean error), and other measures > > obtained by using the R verification package. > > > > The example below is limited to 20 records and shows lead_time, > r_squared, > > (forecast) cycle, fcst_date (forecast date) -- the full data set is just > > over 2 years of daily data with 3 forecast cycles (00Z, 12Z, and 18Z) > daily. > > > > >From my query, below) how do I construct an appropriate data structure > to > > analyze & plot the data as monthly averages? > > > > Regards, > > Tom > > > >> q<-dbGetQuery(con,"select lead_time,r_squared,cycle,fcst_date from > > verify_table where duration=6 limit 20") > >> q > > lead_time r_squared cycle fcst_date > > 1 6 5.405095e-02 00 07/31/2010 > > 2 12 5.521620e-06 00 07/31/2010 > > 3 18 1.565910e-04 00 07/31/2010 > > 4 24 8.646822e-02 00 07/31/2010 > > 5 30 1.719604e-02 00 07/31/2010 > > 6 36 5.768113e-04 00 07/31/2010 > > 7 42 2.501269e-06 00 07/31/2010 > > 8 48 6.451727e-02 00 07/31/2010 > > 9 6 2.857931e-01 12 07/31/2010 > > 10 12 1.138635e-01 12 07/31/2010 > > 11 18 2.225503e-02 12 07/31/2010 > > 12 24 1.182031e-03 12 07/31/2010 > > 13 30 8.841142e-04 12 07/31/2010 > > 14 36 1.082490e-01 12 07/31/2010 > > 15 42 1.502887e-05 12 07/31/2010 > > 16 48 NA 12 07/31/2010 > > 17 6 8.689588e-02 00 08/01/2010 > > 18 12 5.884336e-04 00 08/01/2010 > > 19 18 2.219316e-07 00 08/01/2010 > > 20 24 3.960752e-02 00 08/01/2010 > > > > Try this: > > Lines <- "lead_time r_squared cycle fcst_date > 1 6 5.405095e-02 00 07/31/2010 > 2 12 5.521620e-06 00 07/31/2010 > 3 18 1.565910e-04 00 07/31/2010 > 4 24 8.646822e-02 00 07/31/2010 > 5 30 1.719604e-02 00 07/31/2010 > 6 36 5.768113e-04 00 07/31/2010 > 7 42 2.501269e-06 00 07/31/2010 > 8 48 6.451727e-02 00 07/31/2010 > 9 6 2.857931e-01 12 07/31/2010 > 10 12 1.138635e-01 12 07/31/2010 > 11 18 2.225503e-02 12 07/31/2010 > 12 24 1.182031e-03 12 07/31/2010 > 13 30 8.841142e-04 12 07/31/2010 > 14 36 1.082490e-01 12 07/31/2010" > > library(zoo) > q <- read.table(text = Lines) > > z <- read.zoo(q, index = 4, FUN = as.yearmon, format = "%m/%d/%Y", > aggregate = mean) > plot(z) > > See the 5 vignettes that come with zoo as well as ?read.zoo, ?plot.zoo > and ?xyplot.zoo > > > -- > Statistics & Software Consulting > GKX Group, GKX Associates Inc. > tel: 1-877-GKX-GROUP > email: ggrothendieck at gmail.com > -- Thomas E Adams National Weather Service Ohio River Forecast Center 1901 South State Route 134 Wilmington, OH 45177 EMAIL: thomas.ad...@noaa.gov VOICE: 937-383-0528 FAX: 937-383-0033 [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.