similar to: date & time manipulation- R 2.15.1 windows 7

I'm still having trouble getting to grips with time classes. I wish to calculate the difference in days between events. Browse[1]> insp.j$First [1] "2002-02-19 13:00:00 NZDT" Browse[1]> spray.j$Date [1] "2001-11-29 13:00:00 NZDT" Browse[1]> insp.jk - spray.j$Date Time difference of 82 days If I save insp.jk to a vector, I get a nice useful value of 82.

Hi All, I have an script in R which accepts user inputs for certain parameters, particularly dates, which the user inputs as character strings. eg: > date1 <- "2009-01-21" The script later parses the input via the as.Date function: > as.Date(date1) However, as.Date encounters an error when the string does not represent an actual date. eg: > date1 <-

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 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 am trying to calculate the median of each row of a data frame where the data frame consist of columns of class Date. Below are my test data and best attempt at using apply. I didn't see a solution via Google or the Baron search site. I'd be grateful for any suggestions or solutions. I'm using R 2.0.0 on Mac OS X. Thank you, Stephen Weigand ### Test data date1 <- c(1000,

Hello all, Can somebody point me to references or provide some code on dealing with this date issue. Basically, I have two vectors of values that represent dates. I want to convert these values into a date format and subtract the differences to show elapsed time in days. More specifically, here is the example: Date1 Date2 032398 061585 032398 061585 111694 101994 111694

Hi, ?In the example you provided, it looks like the dates in Date2 happens first.? So, I changed it a bit.? DataA<- read.table(text=" ID,Status,Date1,Date2 ??? ??? ?????? 1,A,3-Feb-01,15-May-01 ??? ??? 1,B,15-May-01,16-May-01 ??? ??? 1,A,16-May-01,3-Sep-01 ??? ??? ??? ??? ??? 1,B,3-Sep-01,13-Sep-01 ??? ??? ??? ??? ??? 1,C,13-Sep-01,26-Feb-04 ??? ??? ??? ??? ???

Full_Name: Alexander L. Belikoff Version: 2.8.1 OS: Ubuntu 9.04 (x86_64) Submission from: (NULL) (67.244.71.200) I'm trying to reshape the following data frame: ID DATE1 DATE2 VALUE_TYPE VALUE 'abcd1233' 2009-11-12 2009-12-23 'TYPE1' 123.45 ... VALUE_TYPE is a string and is a factor with only 2 values

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

I searched for forum for something about this but couldn''t find anything. For example I have this in my view: (you enter start/end dates from dropdowns, pick a category and a report is generated.) <%= start_form_tag :action => ''display_report'' %> From: <%= date_select ''report'', ''date1'' %> <br /> To: <%=

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

i have a data frame with 2 columns of dates. with str(dataframe) i have ensured myself that they were indeed formatted as dates. one column has NA's in it. the aim is now to make a third column that chooses date1 if it is a date, and choose date2 if it is a NA. i am trying df$date3=ifelse(is.na(df$date1), df$date2, df$date1). this leads to unexpected behaviour: the resulting column is

Hi all, following sample code illustrates the problem : Date1 <- Date2 <- as.POSIXlt(seq.Date(as.Date("2010-04-01"),as.Date("2011-04-01"),by='day')) identical(Date1,Date2) all.equal(Date1,Date2) identical() gives the correct answer. As there is no all.equal method for POSIXlt objects, all.equal.list is used instead. Subsetting using [[]] doesn't work

hi, Is there an easy way of calculating the difference in months between two dates in a controller. thanks -- Posted via http://www.ruby-forum.com/.

Hi, I''m trying to use ParseDate within a for loop but I get this error: can''t dup NilClass Any suggestions for making this work? Thanks, -Jason

Folks: With the help of David L. Reiner, I've developed a function that computes the number of months between 2 dates, x and y. num.months <- function ( x , y ) { x <- as.Date( x ) y <- as.Date( y ) seeq <- seq(from=x , to=y , by="months") ans <- length( seeq ) - 1 if ( max( seeq) > y ) ans <- ans -1 ans } To ease your reading this function, I've

I understand that the two following loops should produce the exact same output. However, they do not. It appears that looping directly through the sequence of Date objects somehow makes them be coerced to numeric: > date1 = "20130301" > date2 = "20130302" > > d1 = as.Date(date1, format="%Y%m%d", tz="GMT") > d2 = as.Date(date2,

I wasn't even aware I was using midnightStandard. You won't find it in my script. Here is the relevant loop: date1 = timeDate(charvec = Sys.Date(), format = "%Y-%m-%d") date1 dow = 3; for (i in 1:length(V4) ) { x = read.csv(as.character(V4[[i]]), header = FALSE, na.strings=""); y = x[,1]; year = V2[[i]]; week = V3[[i]]; dtstr =

Hi there, I have data frame with columns ID and Date. There are multiple rows for each ID, but I only want to keep the *first* such row--i.e., the row corresponding to the earliest event. So if I had, say, 1000 rows of 100 IDs doing an average of ten events each, I'd run this trimming procedure and end up with a data frame containing 100 rows (one for each ID), where each row record that

Hi R users, I need your help to write a code in r that does the following calculation from three different datasets; ac = 1/sum (NPP from date 1 to date 2, dataset=1) * (biomass at date 2 -biomass at date 1, dataset = 2) + (littfall at date 2, dataset=3). all the dates are in yr-month-day format. Which library or function Should I use to tell R do these calculations of these variables at