similar to: Treatment of Date ODBC objects in R (RODBC)

Although the documentation is somewhat sketchy, I() can be used to create objects of class AsIs: > I("a") [1] "a" attr(,"class") [1] "AsIs" "character" > I(4) [1] 4 attr(,"class") [1] "AsIs" "numeric" > I(4 + 0i) [1] 4+0i attr(,"class") [1] "AsIs" "complex" > This

I have a frame which contains 3 columns: "date" "defectnum" "state" And I want to get the most recent state change for a given defect number. date is POSIXct. I have tried: aggregate(ev$date, by=list(ev$defectnum), max) Which appears to be working except that the dates seem to come back as integers (presumably the internal representation of POSIXct). When I

Dear All, The recent improvement in RODBC to recognize datetimes in tables has exposed my ongoing confusion. All my data are obtained from a satellite system (Argos) which tags events in the GMT time zone. Daylight saving is ignored. To my way of thinking this means that 1. twelve-o-clock means halfway through the day regardless of season, and 2. the difftime of any two dates where

I am a beginner in R with a background in SAS. Are there built-in R methods of reading dates for calculating elapsed days between two calendar dates? If so, are there any examples I can browse? Thanks in anticipation. John Byrne. Lecturer in Information Systems. Australian Catholic University.

I'd like to make a plot showing frequency of an event. The data is in a data from that includes Year, Month and Day (of month) fields, so I created a Date with ISOdate(Year, Month, Day, tz=''). I can plot frequencies for the year 2002 with > thisyear <- Date[Year==2002] > hist( thisyear, xaxt='n' ) > axis.POSIXct( 1, at=seq(min(thisyear), max(thisyear),

Hi all, I'm having difficulty converting a 'dates' object to a POSIXct object: testDATES<-c(35947,35971,36004,36008,36053,36066) testDATES<-chron(dates=testDATES, format = c(dates = "m/d/y"), origin=c(month = 12, day = 30, year = 1899)) >[1] 06/01/98 06/25/98 07/28/98 08/01/98 09/15/98 09/28/98 > as.POSIXct(testDATES) [1] NA NA NA NA NA NA

I use POSIXct for datetimes. Is thee a timeAlign function that I can use where : align by year direction -1 ==> start of this year direction 1 ==> start of next year align by week direction -1 ==> date on last sunday direction 1 ==> date on next sunday align by day direction -1 ==> time at past midnight direction 1 ==> time at this comming

Hello all! Can someone confirm whether there is a bug or not? I was trying to use sqlUpdate in place of sqlSave as data set I import has duplications. However I get errors while using fast=FALSE argument to safely update/ignore duplicates: Error while executing the query[RODBC] ERROR: Could not SQLExecDirect 'UPDATE "data" SET "logger"=1,

Dear list: working with date/times I have come across a problem that ISOdate and ISOdatetime are too slow on large vectors of data. I was surprised just until I looked at the implementation and the man page: "ISOdatetime and ISOdate are convenience wrappers for strptime". In other terms, they convert data to character representation first in order to create a POSIXlt object that is then

For the r script below >datestr <- "01/01/2004" >as.POSIXct(as.Date(datestr, "%d/%m/%Y")) I get the following output "2003-12-31 18:00:00 Central Standard Time" Why is the date a day before. I guess its something to do with the time, but is there a way to get it to return 2004-01-01 instead? Thanks in advance... -Sandeep [[alternative HTML version

I am trying to plot a image where the x axis has the units of time. When I issue the image(x,y,z) command with x as a POSIXct object, it fails to put a time stamp on the x axis. Instead I get a warning "Incompatible methods" warning and no dates on my x axis. This example shows my problem: Rmat=t(matrix(data=rnorm(1:500),ncol=10,nrow=50)) tax=seq(ISOdate(2010,4,14,12,0,0),

Hi, i'm trying to read some data from excel files but it seems that neither xlsReadWrite nor sqlFetch (RODBC) doesn't like the format (Excel 5.0). When i open the file in Excel and save it in a new format Excel 97 -2003 everything works fine. Is it possible to use ODBC connection to open old format files, or i guess i will have to open and save every file in Excel in new format, which

Hello, I am fairly new to R and its connectivity to MS-Access. I just installed RODBC and it seems to be working well except when I use the date to condition the query. For example the query below sqlQuery(channel, "select date from tblUScpi where (date > d2) order by date") returns the following error [1] "[RODBC] ERROR: Could not SQLExecDirect"

Dear R-helpers, I have a problem converting an object made with the 'chron' function to a POSIXct object: # Make date based on DOY dat <- chron(dates=232, origin.=c(month=1, day=1, year=2008)) dat #[1] 08/20/08 # Converting to POSIXct uses current timezone (Sydney): as.POSIXct(dat) #[1] "2008-08-20 10:00:00 EST" # Setting GMT timezone has no effect? as.POSIXct(dat,

Hi R, I have an excel file in which the third column is "date" and others are "character" and "numeric". Number of columns are 12 If I use this to read the file in R: x = read.xls("D:\\file.xls") The problem is that my date column is read in julian dates. So I am using: x = read.xls("D:\\file.xls",

I am having a series of problems using date time data that has been converted into a POSIXt and POSIXlt classes. I have hourly time series data from 1900 that has been converted from text data. I assume most of my problems come from a mis-underdanding of the POSIX class. My matrix named (aa) for this year is approx 8700 by 4. When I try to calculate the length of posit column ( which is the

I am using R-1.7.0 and have some data which consist of one vector of numbers and a second corresponding vector of dates belonging to the POSIXct class. I would like to plot the numbers against the dates. What is the best way to do this? It almost works to just call `plot.' However if I do this while using the `ylab' parameter I get a warning message: parameter "ylab"

Hi, I am new to R, coming from a few years using Stata. I've been twisting my brain and checking several R and S references over the last few days to try to solve this data management problem: I have a data set with a unique patient identifier that is repeated along multiple rows, a variable with month of patient encounter, and a continous variable for cost of individual encounters. The data

Dear all, I have found the following (for me) incomprehensible behaviour of ISOdate (POSIXct): > ISOdate(1900,6,16) [1] "1900-06-15 14:00:00 Westeurop?ische Sommerzeit" > ISOdate(1950,6,16) [1] "1950-06-16 14:00:00 Westeurop?ische Sommerzeit" Note that in the first case I get the 15th of June back, not the 16th as I would have expected! This happened under R-1.7.1 on

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]]