similar to: Bug in seq.date?

Dear all, I've been struggling to perform common operations on dates that I need to be able to correct draw date-time scales - in particular I need to be able to round/truncate/ceiling dates to arbitrary precision - e.g. to weeks, months or years (or multiples thereof). I haven't been able to find anything to do this in base R (trunc.Date only truncates to sub-day units), or in the date

Dear "R-listers" I've been trying to figure out how to annotate charts in ggplot (ie add text to line charts, highlighted boxes etc). By and large, I can get close to what i want with base graphics, but would ideally like to use ggplot whenever possible (additionally, i would like to add text labels automatically to the chart). The code is below I suspect I need to use geom_rect,

Hi, I have some confusion in applying a function over a column. Here's my function. I just need to shift non-March month-ends to March month-ends. Initially I tried seq.dates, but one cannot give a negative increment (decrement) here. return(as.Date(seq.dates(format(xdate,"%m/%d/%Y"),by="months",len=4)[4]) ) Hence this simple function: > mydate <-

Dear R gurus, I am currently using the chron package for date manipulation in R and I am able to control the date which take the format - 1998/07/03, and - 2006-09-15 (date without time) Library(chron) As.Date(2006-09-15, format = '%Y-%m-%d') However I have a problem with the date containing only the year and month (i.e. 2006-09, 2007/08, 200609).

Hello Everyone,I think this is a very simple problem, I have been struggling with it for a few days now. I have a 10-year daily data in the following format. Date A B C D E 1978-10-22 18 20.64 0.0 0.176 -1.76 1978-10-23 15 17.06 0.4 0.147 2.52 1978-10-24 3 7.588 0.0 0.068 -6.86 1978-10-25 9 11.491 0.0 0.102

New user here. My goal is pull daily averages from a long dataset. I've been working with some code I got from this list from https://stat.ethz.ch/pipermail/r-help/2009-March/191302.html The code how I have been using it is as follows: library(zoo) library(chron) DB<-read.table("/Users/me/Desktop/R/data.csv", sep=",", header=TRUE, as.is =TRUE) z<-zoo(LTER6$temp,

Hi all, Please, how could I calculate the time that two time segments has in common? Is there any function to perform this calculation? For instance, given four POSIXlt objects... endPeriod<-as.POSIXlt("2008-09-30") startPeriod<-as.POSIXlt("2007-10-01") endProject<-as.POSIXlt("2007-05-31") startProject<-as.POSIXlt("2006-12-01") that limit

Dear R users: I have a data set that looks something like this: ID time y 1 2/01/2008 4 1 2/09/2008 12 1 9/01/2008 8 2 1/06/2008 3 2 3/01/2008 4 2 3/09/2008 9 2 6/03/2008 4 3 1/02/2008 3 3 1/10/2008 8 3 2/02/2008 7 3 2/10/2008 3 I'd like to sum up the weekly data to the monthly level, so that it looks something

I am was going to look at the as.yearmon function in the zoo package and write a as.day function to aggregate a time series of 96 observations per day into the mean for each day, but I don't know how to look at the code so that I can convert it into something I can use. On top of that I believe that it is probably an S3 method and I haven't quite gotten that far in my programming

Hello everyone, I have a data generated in a way similar to the following library(chron);library(zoo) date<- seq(as.Date("1990-01-01"),, as.Date("2000-12-31"), by = 1) obs<- zoo(rnorm(length(date), mean = 10, sd = 2.5), order.by = date) monthly<- function(date) as.Date(as.yearmon(Date)) result<- data.frame ( Date = obs = aggregate(obs, monthly, sum)) Now, I want

hi everyone! hope you can help me here. i am a new R user. what i am trying to do is to find the maximum annual discharge from a daily record. i have a data.frame which includes date and the discharge. somewhat like this.. 10/1/1989 2410 10/2/1989 2460 10/3/1989 2890 ... ... ... 12/31/2005 5730 i have been browsing through the archives and fount out about the aggregate

Hi, What is the reason for seq.Date to require the 'by' argument and not to default it to 1 in the example below? > seq(from=as.Date("1996-01-01"), to=as.Date("1996-12-01")) Error in seq.Date(from = as.Date("1996-01-01"), to = as.Date("1996-12-01")) : exactly two of `to', `by' and `length.out' / `along.with' must be specified

#the below code is the way that I would like the plot to look. I have tried to write a panel function: my.panel <- function(x, y, ..., pf = parent.frame()) { axis(side=1, at = seq(rng[1], rng[2], 1/12), labels = n, tcl = -0.3) } #but it does not work and I am at a loss and help would be appreciated. I will use this for multiple library(zoo) library(chron) #this is what I would like the

I know that I can use as.yearmon in the package "zoo" to find the year and the month of a date. I can use as. yearqtr to find the year and the quarter. But how can one find just the year of a date? Thanks a lot! -- Dimitri Liakhovitski Ninah Consulting www.ninah.com

I have a vector of dates. I wish to find the month end date for each. Any suggestions? e.g. For 12/15/05, I want 12/31/05, For 10/15/1995, I want 10/31/1995, etc __________________________________________________ [[alternative HTML version deleted]]

Dear all, I have a date related question. Suppose I have a character string "March-2009", how I can convert it to a valid date object like as.yearmon("2009-01-03") in the zoo package? Is there any possibility there? Ans secondly is there any R function which will give the names of of all months as "LETTERS" does? Thanks for your time. [[alternative HTML version

To the R development team; I found an unusual behavior in zoo when I upgraded to R 2.11.0 - it abruptly terminated when I performed certain operations on large zoo objects. I sent an e-mail to Achim Zeileis and he said this was a potential bug that I should report to the R development team. The details are given below in the thread below. Basically, I can crash R with this code: library(zoo)

Sorry, this is my first time to post. I have a big data set: first colume is date (ex: 2008-2-150, the second is time (10:30:00), and the following columes are variaty measurement data. Every 30 min, I have one data. I want to find an effecient way to calculate the hourly, daily, monthly and yearly average, and plot them, and eventually use these average data to do further analysis. Thanks!

Hi all, please see my code: > library(zoo) > a <- as.yearmon("March-2010", "%B-%Y") > b <- as.yearmon("May-2010", "%B-%Y") > > nn <- (b-a)*12 # number of months in between them > nn [1] 2 > as.integer(nn) [1] 1 What is the correct way to find the number of months between "a" and "b", still

Dear R helpers. I am new to plotting time data using R. wonder how to convert character time info into date in R. I searched over the web but did not find answer. the input character string is something like 03_1993 or 03-1993, so the precision is at month level. I tried the following but failed. #R code below. strptime(c("03_1993"),"%m_%Y")