similar to: Representing 'Date' as 'Year - Quarter'

Hello, I have two date strings, say "1972-06-30" and "2012-01-31", and I'd like to get every quarter period end date between those dates? Does anyone know how to do this? Speed is important... Here is a small sample: Two dates: "2007-01-31" "2012-01-31" And I'd like to get this: [1] "2007-03-31" "2007-06-30"

Consider the following scrap of code: > x<- ts(1:50,start=c(1,11),freq=12) > y <- aggregate(x,nfreq=4) > c(y) [1] 6 15 24 33 42 51 60 69 78 87 96 105 114 123 132 141 > y Error in rep.int("", start.pad) : invalid number of copies in rep.int() > tsp(y) [1] 1.833333 5.583333 4.000000 So we can aggregate into quarters, but we cannot print it using

Consider the following scrap of code: > x<- ts(1:50,start=c(1,11),freq=12) > y <- aggregate(x,nfreq=4) > c(y) [1] 6 15 24 33 42 51 60 69 78 87 96 105 114 123 132 141 > y Error in rep.int("", start.pad) : invalid number of copies in rep.int() > tsp(y) [1] 1.833333 5.583333 4.000000 So we can aggregate into quarters, but we cannot print it using

I have time series observation on daily frequencies : library(zoo) SD=1 date1 = seq(as.Date("01/01/01", format = "%m/%d/%y"), as.Date("12/31/02", format = "%m/%d/%y"), by = 1) len1 = length(date1); data1 = zoo(matrix(rnorm(len1, mean=0, sd=SD*0.5), nrow = len1),  date1) plot(data1) Now I want to calculate 1. Quarterly statistics like mean, variance etc

I have a data set with quarterly time series for several variables. The time index is recorded in column 1 of the dataframe as a character vector "Q1 1961", "Q2 1961","Q3 1961", "Q4 1961", "Q1 1962", etc. I want to produce line plots with ggplot2, but it seems I need to convert the time index from character to date class. Is that right? If so, how

I have a dataframe say: date price_g price_s 0.34 0.56 0.36 0.76 . . . . . . and so on. say, 1000 rows. Is it possible to add two columns to this dataframe, by computing say diff(log(price_g) and diff(log(price_s)) ? The elements in the first row of these columns cannot be computed, but

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

On Sun, 28 Jan 2018, phil at philipsmith.ca wrote: > I have a data set with quarterly time series for several variables. The > time index is recorded in column 1 of the dataframe as a character > vector "Q1 1961", "Q2 1961","Q3 1961", "Q4 1961", "Q1 1962", etc. I want > to produce line plots with ggplot2, but it seems I need to

Using Achim's d this also works to generate z where FUN is a function used to transform the index column and format is also passed to FUN. z <- read.zoo(d, index = "time", FUN = as.yearqtr, format = "Q%q %Y") On Sun, Jan 28, 2018 at 4:53 PM, Achim Zeileis <Achim.Zeileis at uibk.ac.at> wrote: > On Sun, 28 Jan 2018, phil at philipsmith.ca wrote: > >> I

date <- as.POSIXlt(Sys.time()) #present date for (i in 1:difftime(as.POSIXlt(Sys.Date()),"2007-10-01")) if (date$wday != 0 & date$wday != 6) {print(date);assign("date", (date-86400))} else (assign("date", (date-86400))) I am trying to print dates from present day to a day in the past, but omitting weekends. I am not doing something right, but can't

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 =

I am trying to download a bunch of files from a server, for which I am using download.file( ) within a for loop. The script is working fine except until download.file hits a URL which has no file, at which point it exits. I want to change this behavior to simple log the failure and maintain state within the for loop and iterate to next. I read about try / tryCatch but am having trouble

Hello, I am writing codes for time series computation but encountering some problems Given the quarterly data from 1983Q1 to 1984Q2 PI1<-ts(c(2.747365190,2.791594762, -0.009953715, -0.015059485, -1.190061246, -0.553031799, 0.686874720, 0.953911035), start=c(1983,1), frequency=4) > PI1 Qtr1 Qtr2 Qtr3 Qtr4 1983 2.747365190 2.791594762

Can someone throw light on the following problem I am having with RODBC? There's an Excel file I am trying to read from, it has one sheet named 'nameclass'. Thanks in anticipation. Vishal Belsare > library(RODBC) > con = odbcConnectExcel(file.choose()) > tbls <- sqlTables(con) > tbls TABLE_CAT TABLE_SCHEM TABLE_NAME TABLE_TYPE REMARKS 1

Is there any existing implementation in R/S of : 1] Pincus & Kalman's approximate entropy (ApEn) measure 2] Total Correlation / Multiinformation 3] Information Interaction A search doesn't quite reveal anything, but I'd be keen to not reinvent in case someone has worked on it. Many thanks in anticipation. Best, Vishal Belsare

Gabor, Thanks much. Your solution is elegant. My overall scheme is to take present date, and check whether it is a weekend, if not, then create a string based on the date, to concatenate into a url link for download.file( ). The files I need to download have a part which is in the format: mmddyy. I am working to make myself a system to connect to exchanges, and download end of day files from

I have an ordered series of 3 month t-bill rates (annual). I transform this to a daily series, however, the observations are constructed only from the dates on which the t-bills were issued, which is every week. So now I have ordered observations of the daily 'risk-free rate' for one day every week. I want to expand this zoo object to give a value for every day, and to do so, copy the

I am trying to generate a line graph with quarterly time buckets (with nice labels) on the x-axis. The first block of code below will generate the graph with nicely formatted x-axis labels, but the "type=" and "col=" options are not recognized when factors are used for the x-axis. The second block, where the quarter values are mapped into dates, will plot the line nicely but

Folks, I want to make the following function more efficient, by vectorizing it: getCriterionDecisionDate <- function (quarter , year) { if (length(quarter) != length(year)) stop ("Quarter and year vectors of unequal length!"); ret <- character(0); for (i in 1:length(quarter)) { currQuarter <- quarter[i]; currYear <- year[i]; if ((currQuarter < 1) |

I am interested in creating multiple (say 1000) time series, from a given stochastic process, of length 250. I want to refer to each realization with its own variable name, of the format say, tsn, where n is the n'th simulation. i.e. ts1, ts2, ts3, ts4, .... , ts1000 The way I am thinking of doing this is placing the following code within another loop, and the 'tsn' assignment should