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

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

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

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

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,

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 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

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),

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"

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

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 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

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),

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

Hi all, I would like the following code to work, but it doesn't: library(DBI) library(RODBC) m <- dbDriver("RODBC") # Example for dbConnect(DBI), causes error m <- dbDriver("ODBC") # Example for DBIDriver-class(DBI), causes error The errors are: Error in do.call(as.character(drvName), list(...)) : could not find function "RODBC" (substitute

Hello, For basic date time arithmetics operations, AFAK, there're actually the function difftime() and the (dt + num) operations. I'm wondering if other basic operations exist, like add(dt, num, unit) where unit would be "y", "q", "m", etc. Also for the function seq.dates (or seq.POSIXt), the case for by="months" would be more useful if it

Hello, For basic date time arithmetics operations, AFAK, there're actually the function difftime() and the (dt + num) operations. I'm wondering if other basic operations exist, like add(dt, num, unit) where unit would be "y", "q", "m", etc. Also for the function seq.dates (or seq.POSIXt), the case for by="months" would be more useful if it

hey I am trying to turn a dataframe into xts with the function: as.xts, but it returns the error: Error in as.POSIXlt.character(x, tz, ...) : character string is not in a standard unambiguous format could someone give me some pointers please the data is coming from a spreadsheet via the excel, and has 5 columns of data (date (with the date and time), open, high, low, close) (excel format) ela

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, I've troubles with some difftime objects. e.g. ISOdate(2001, 4, 26) - ISOdate(2001, 2, 26) - 2 works, telling me "Time difference of 57 days". But when I'd like to add days, such as ISOdate(2001, 4, 26) - ISOdate(2001, 2, 26) + 2 the function gives me an error. Function "as.COMDate.chron" of the Rbloomberg package doesn't work for that reason. I'm