similar to: Combining month and year into a single variable

Hello, I am trying to define a different interval for a "year". In hydrology, a "water year" is defined as the period between October 1st and September 30 of the following year. I was wondering how I might do this in R. Say I have a data.frame like the following and I want to extract a variable with the water year specs as defined above:

Hi, I have a query about sqldf, and dates in general. I couldnt find much on the net or on the forums, hence I am here. Here is the issue: I want to write a function that accepts 3 arguments: date1, date2 and a dataframe, say 'df'. Within the function, I want to populate a temp dataframe which essentially contains the output of the query "select * from df where DATE between date1

Hi, Given a date, how do I get the last date of that month? I have data in the form YYYYMM, that I've read as a date using > x$Date <- as.Date(ISOdate(substr(x$YearEnd,1,4),substr(x$YearEnd,5,6),1)) But this gives the first day of the month. To get the last day of the month, I tried > as.Date(as.yearmon(x$Date,frac=0)) But I don't get the last day of the month here. (Tried

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 am currently puzzled by a seach path behavior. I have a library of a dozen routines getlabs(), getssn(), getecg(), ... that interface to local repositories and pull back patient information. All have a the first 6 arguments in common, and immediately call a second routine to do initial processing of these 6. The functions "joe" and "fred" below capture the relevant

Dear R Help, I am trying to get fields showing the last day of each month for a monthly closing project. In order to find the last day of the previous month, I subtract the number of days from the current month. For all months my code works; however, for October, my code doesn't work...it returns 2010-09-*29* instead of 2010-09-*30*. format(strptime("2010-10-31",

Hi Using the ggplot2 package, I would like to obtain a plot that contains two time series that have data points on different dates. For instance, one data frame looks like: date1, value1 2010-01-05, 2921.74 2010-01-08, 2703.89 2010-01-14, 3594.21 2010-01-20, 3659.22 The other data frame looks like date2, value2 2010-01-01, 285.85 2010-01-02, 229.20 2010-01-05, 333.91 2010-01-06, 338.27

Hello, I want to change the day of the month in a date object. What I am doing at the moment is: x=as.POSIXlt(x) x$mday=13 x=as.Date(x) Does anybody know if there is a more "natural" (eficient) way to do this Thank you Felipe Parra [[alternative HTML version deleted]]

Hello! I'd like to take Dates and extract from them months and years - but so that it sorts correctly. For example: x1<-seq(as.Date("2009-01-01"), length = 14, by = "month") (x1) order(x1) # produces correct order based on full dates # Of course, I could do "format" - but this way I am losing the "Date" quality of the data:

Hello, I am looking for a way to subset a data frame by choosing the top ten maximum values from that dataframe. As well this occurs within some factor levels. ## I've used plyr here but I'm not married to this approach require(plyr) ## I've created a data.frame with two groups and then a id variable (y) df <- data.frame(x=rnorm(400, mean=20), y=1:400,

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")

Hi all, I'm having a little bit of trouble with some date conversions and am hoping someone can help me out. Thanks in advance. OK, I have two sources of data that provide date info in a csv file differently. I've attached a small zipped file with two text files that illustrate both. (Is it ok to send attachments to this list? Not sure. It's very small.) I need to be able to

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]]

Hello, I would like to implement a "turn-of-the-month' trading strategy in R. Given a daily series of stock market return data as a zoo object, the strategy would go long (buy) four trading days before the end of the month, and sell the third trading day of the following month. How can I select these days, particularly the fourth day before and the third day after the turn of the

Hi everybody, I am beginer in R and I need your precious help. I want to create a small function in R as in sas to retrieve date. I have a file with data that import in R. DATE PAYS nb_pays.ILI. 1 24/04/2009 usa 0 2 24/04/2009 usa 0 3 24/04/2009 Mexique 0 4 24/04/2009

Hi, I'd like to make a time series at an annual frequency. > a<-xts(x=c(2,4,5), order.by=c("1991","1992","1993")) Error in xts(x = c(2, 4, 5), order.by = c("1991", "1992", "1993")) : order.by requires an appropriate time-based object > a<-xts(x=c(2,4,5), order.by=1991:1993) Error in xts(x = c(2, 4, 5), order.by =

Dear R community, I have the following two zoo objects: MONTHLY CPI > plot(z) > par("usr") [1] 1977.76333 2011.15333 70.39856 227.03744 > z=zooreg(cpius$Value,as.yearmon("1979-11"),frequency=12) > str(z) ?zooreg? series from Nov 1979 to Oct 2010 Data: num [1:372] 76.2 77 77.8 78.5 79.5 80.3 81.1 82 82 82.6 ... Index: Class 'yearmon' num [1:372]

Dear All, While i am trying convert data frame object to zoo object I am getting numeric(0) error in performance analytics package. The source code i am using from this website to learn r in finance: https://faculty.washington.edu/ezivot/econ424/returnCalculations.r # create zoo objects from data.frame objects dates.sbux = as.yearmon(sbux.df$Date, format="%m/%d/%Y") dates.msft =

Hello, probably a newbie question, but i didnt find any information on plotting/regressing w.r.t. a date data type. My trials were unfruitful. Can anyone help ? Thanks in advance! Here is my interaction with R: > tabelle date number date2 1 2009-01-1 1673 2009-01-01 2 2009-12-1 2111 2009-12-01 3 2010-7-1 2487 2010-07-01 4 2013-2-1 4301 2013-02-01 > regression.punkte<-lm(tabelle$number

Hello, In zoo package, if I would like the time frame to be 1981M01 to 1982M12, then I code time_0<-as.yearmon("1981-01")+(0:23)/12 However, if the time frame of interest becomes 1981M01 to 2011M12, it is relatively hard to calculate the number of months. Is there any faster way to do it? Thanks, miao [[alternative HTML version deleted]]