similar to: Calculating difference in variable values (e.g. elapsed time) in data frame

I am trying to create basic descriptive statistics for a spatial dataset using moving windows of variable sizes. I found the filter(dataset, rep(1/a,1)) very useful for obtaining averages for a given moving window size "a" (a is the window size within a column of data in a matrix - the filter is applied to all columns automatically) I could not find anything analogous for

Hello R Freaks, I calculate the difference in days between two events with the following litte R expresseion: T1a <- strptime(T1,"%m/%d/%y %H:%M:%S"); T2a <- strptime(T2,"%m/%d/%y %H:%M:%S"); T1b <- as.Date(T1a); T2b <- as.Date(T2a); days <- T2b-T1b; time <- T2a - T1a; In the project I would like to calculate only working day. I the a possibility to count

R-Devel, I store and retrieve a large amount of financial data (millions of rows) in a PostgreSQL database keyed by date (and represented in R by class Date). Unfortunately, I frequently find that a great deal of processing time is spent converting dates from character representations to Date class representations in R, presumably because strptime is not fast for large vectors (>10,000

[I am herewith re-posting this message on R-devel, as it seems to be the most appropriate mailing list for this issue.] Dear List, >From what I understand, strptime() simply converts from one class representation to another; i.e., from character to POSIXct/POSIXlt. One strange feature of this command running on Linux is that there are repeated calls to system time (as was revealed

Hi I have data for events in rows, with columns for person and date. Each person may have more than one event; tC <- textConnection(" Person date bob 1/1/00 bob 1/2/00 bob 1/3/00 dave 1/7/00 dave 1/8/00 dave 1/10/00 kevin 1/2/00 kevin 1/3/00 kevin 1/4/00 ") data <- read.table(header=TRUE, tC) close.connection(tC) rm(tC) I would like to add a new column to my dataframe containing

Hello, I would like to run a series of regressions on my data (response variable over time): 1) regression from T1 to T2 2) regressions from T1 through T3 3) regression from T1 through T4, etc. I have been struggling to find a way to do this through commands, as opposed to cutting up the data manually (my dataset has over 6000 rows/observations). An illustrative dataset can be created thusly:

I think the following examples illustrate the crux of the matter (version and OS info are below). The problem has to do with the transition from standard time to daylight savings time. My timezone, US/Pacific, has two parts: standard time (PST) 8 hours behind GMT and daylight savings time (PDT) 7 hours behind GMT. The transition takes place this year on 7 April at 02:00, when 02:00 is

Hi This code should explain what I'm trying to do > strptime("30-Jan-08", "%d-%b-%y") [1] "2008-01-30" > > format(strptime("30-Jan-08", "%d-%b-%y") , "%b-%y") [1] "Jan-08" > > strptime(format(strptime("30-Jan-08", "%d-%b-%y") , "%b-%y") , "%b-%y") [1] NA I have a

Hi All In trying to correlate some tide gauge data I need to deal with varying timezones. From the documentation on strptime, it seemed that the tz variable might have some effect on the conversion, but I'm not seeing an effect. > strptime("20061201 1:02 PST",format="%Y%m%d %H:%M",tz="PST")+0 [1] "2006-12-01 01:02:00 EST" >

Hi list, Could someone explain to me why the following result is not a integer? > difftime(strptime("24NOV2004", format="%d%b%Y"), strptime("13MAY2004", >format="%d%b%Y"), units="days") Time difference of 195.0417 days I'm using R2.12.0 on WinXP. Thanks! ...Tao

I'm trying to proess date/time fields from files that were given to me to analyze. Any clues what I'm doing wrong with strptime? This seems to fail the same way under Linux or Windows. For ?strptime would it make sense to explain %OS3 somewhere besides the Examples? > # Why does %OS3 work here? > format(Sys.time(), "%H:%M:%S") [1] "16:45:19" >

Dear list members, I have come about a peculiar behavior in R (4.0.2) which I would describe as a bug. On macOS, where `strptime()` raises a warning for invalid timezone identifiers, the following code will continue to raise the original warning with every subsequent call to `strptime()`: ``` # attach a handler for warnings for this call only: tryCatch(strptime('2020-10-31 18:30', format

Hello, I cannot reproduce this behavior and, as documented, the posted code doesn't issue warnings due to a wrong timezone but I'm running sessionInfo() R version 4.0.3 (2020-10-10) Platform: x86_64-pc-linux-gnu (64-bit) Running under: Ubuntu 20.04.1 LTS Matrix products: default BLAS: /usr/lib/x86_64-linux-gnu/blas/libblas.so.3.9.0 LAPACK:

Hi I'm fairly new to R and the list, so please take what I say accordingly! Far as I can see, strptime gives you a string in some specified format. In order to do any kind of numerically-based modelling with that, you need to obtain a number to work with. One way to do this is by getting the time with Sys.time() instead and coercing it to a number using as.integer(): >

Hi, I am having a trouble parsing dates using strptime() that I get in the format of year and week number. The data looks like this "201127" which means year 2011 and week 27. I would like to graph this using ggplot but then I get a gap between 201054 and 201101 so I thought I would just easily convert it. I tried to use strptime and as.Date and the format string of %Y%W but it seems

Hi Frederik, On Mon, 2017-01-16 at 18:20 -0800, frederik at ofb.net wrote: > Hi R Devel, > > I wrote some code which depends on 'strptime' being able to parse an > incomplete date, like this: > > > > > base::strptime("2016","%Y") > [1] "2016-01-14 PST" > > The above works - although it's odd that it gives the month

Hi List, I have one column of beginning dates and one column of ending dates, I want to find their difference. And I want to ignore the trailing zeros, basically everything after the first colon mark. Begin_date End_date 01JAN2000:00:00:00:000 02FEB2002:00:00:00:000 24MAR2012:00:00:00:000 18MAY2012:00:00:00:000 01OCT2003:00:00:00:000

Hi, Does anyone know how to take a time difference when the format of the time is as 13:22:23.586? I am trying to take the difference of time between stock transactions and need to keep the three decimal places for seconds. I have tried *diff(strptime(x, "%H:%M:%S.000))*, but apperantly that doesn't work. Carol Gao [[alternative HTML version deleted]]

Hi, I've been playing with: > joinDate <- format(strptime(as.vector(forum[,2]), "%d-%b-%y"), + "%d-%b-%Y") > today <- format(strptime(as.vector("14-Jun-04"), "%d-%b-%Y"), + "%d-%b-%Y") > joinDate [1] "04-Feb-2004" "13-Feb-2004" "26-Feb-2004"

There is incompatibility between R strptime and musl libc. I posted about it on their mailing list, but they need more information I can't provide, so I'm forwarding the message here in hope R developers can help. Thanks. ---------- Forwarded message ---------- From: Rich Felker <dalias at libc.org> Date: Thu, Feb 4, 2016 at 2:07 PM Subject: Re: [musl] strptime() question To: Alba