On Mon, 2 Jan 2012, Gabor Grothendieck wrote:
Assuming you need a separate column for each site see the read.zoo split= argument. An example is here: http://r.789695.n4.nabble.com/building-time-series-zoo-its-from-a-data-frame-tp2240349p2240814.html
I created a new data frame for a single stream and it has this structure: str(burns.tds) 'data.frame': 2472 obs. of 3 variables: $ site : Factor w/ 137 levels "BC-0.5","BC-1",..: 5 5 5 5 5 5 5 5 ... $ sampdate: Date, format: "1992-03-27" "1992-04-30" ... $ quant : num 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 8.08 ... This is in 'long' form with the date as the second column: head(burns.tds) site sampdate quant 599 BC-3 1992-03-27 0.1 600 BC-3 1992-04-30 0.1 601 BC-3 1992-05-30 0.1 603 BC-3 1992-06-19 0.1 1214 BC-3 1992-07-20 0.1 1215 BC-3 1992-08-10 0.1 I've read the read.zoo help and above URL and cannot get the syntax correct. Emulating the example at the bottom of the referenced Web page produces an error that I interpret as a need to exclude NAs. Adding na.omit to the command still produces an error: burns.tds.z <- read.zoo(burns.tds, split = 1, format = "%Y-%m-%d", na.omit) Error in strptime(format(x, scientific = FALSE), tz = tz, format = format): invalid 'tz' value How do I resolve this invalid 'tz' value? Or, is there another problem but this is the error presented to me? Rich ______________________________________________ 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.