In the text file pressione2008.csv I have the following "Data","MAX","MIN","Note" "07-01-2008 08:00:00", 135, 90, "Eccessi feste, inizio dieta" "07-01-2008 18:00:00", 135, 85, "" "08-01-2008 08:00:00", 125, 75, ""
which is a collection of blood pressure data at different time of the day. I would like to build an its with MIN & MAX blood pressure but being a real newbye with zoo I obtain the following > library(zoo) pressione <- data.frame(read.csv("pressione2008.csv")) miedate <- strptime(as.character(pressione[,1]), format="%d-%m-%Y %H:%M:%S") > miedate [1] "2008-01-07 08:00:00" "2008-01-07 18:00:00" "2008-01-08 08:00:00" > str(miedate) POSIXlt[1:9], format: "2008-01-07 08:00:00" "2008-01-07 18:00:00" ... > ts<- as.zoo(matrix(pressione[,2:3],ncol=2), miedate) > ts Error in Ops.POSIXt(freq, d) : * not defined for "POSIXt" objects > ts<- zoo(matrix(pressione[,2:3],ncol=2), miedate) Error in order(x, ..., na.last = na.last, decreasing = decreasing) : unimplemented type 'list' in 'orderVector1' In addition: Warning message: In zoo(matrix(pressione[, 2:3], ncol = 2), miedate) : some methods for "zoo" objects do not work if the index entries in 'order.by' are not unique > Please help Ciao Vittorio ______________________________________________ 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.