similar to: Coercing in R and in C (R-Extensions)

A newbie here - please forgive me if this is a basic question. We have an in house package built in R 2.2.1 (yes we're a little behind the times at our firm)and would like to rebuild it using R 2.5.1. However, when I try and build the package from source, I keep getting this error: Error in as(slotVal, slotClass, strict = FALSE) : no method or default for coercing "POSIXt"

Hello folks, I found a strangeness while experimenting with POSIXct vectors and lists. It seems that coerced NA's aren't "real" NAs, at least as considered by is.na()? > date_vec = c(as.POSIXct(now()), as.POSIXct(now()+1),NA,"b") > date_vec [1] "2012-08-22 15:00:46 COT" "2012-08-22 15:00:47 COT" NA [4] NA Warning message: In

Something has changed in the S4 default for coercing. Am I now suppose to use setAs, or is there something else I should do to make this work: R version 2.7.0 (2008-04-22) .... > require("methods") > setClassUnion("OptionalPOSIXct", c("POSIXct", "NULL")) [1] "OptionalPOSIXct" > setClass("TSmetax",

Any idea why CHAR(asChar(STRING_ELT( produces NA whereas CHAR(STRING_ELT( gets a pointer to a string? It's generally expected that STRING_ELT should already be a character, but why the coercion does not work? Here is a simple example (consistent over R2.5.1-R2.6 rev 42284, I didn't check earlier versions, but it used to be different in 2.4): install.packages("inline")

Under platform i686-pc-linux-gnu arch i686 os linux-gnu system i686, linux-gnu status major 1 minor 6.1 year 2002 month 11 day 01 language R > x <- strptime(c('10/10/1969','12/31/2002'),format='%m/%d/%Y')

The old factor() wars...... {{maybe don't just report that factor()s are broken by design..}} If ff is a factor, e.g., ff <- as.factor(rep(1:2,3)) f2 <- ff; levels(f2) <- c("Lo","Hi") 1) we don't allow {in R as in S-plus 3.x} arithmetic on factors, i.e. 1 + ff gives an error, and I think most of us believe this is as desired. {{if one

Hi. This feels like a bug to me, or at least an undocumented feature, but I thought I'd see what people here thought of it. Consider a POSIXlt object like this one: > a <- as.POSIXlt ("2011-01-23 12:45:45") > class (a) [1] "POSIXlt" "POSIXt" Fine. Now, if I do some arithmetic on that object, the result is converted to POSIXct. > class (a

Hi all- terribly beginner question here, but I can't figure out how to put dates as the values for my x range in a plot. Example: xrange <- results$current yrange <- results$DIFF plot(xrange, yrange, type="n", xlab="Date", ylab="Differential") lines(results$DIFF, type="l", lwd=1.5, col="red") Where xrange is: > xrange [1]

G'Day, I'm a little confused why the c function has the followng effect on classes - is this a feature ? My workround [ class(cc) <- c("POSIXt", "POSIXct") ] seems to do the job. Many thanks Bernie McConnell "R version 1.3.1, 2001-08-31" on NT > aa <- as.POSIXct("2001-09-23") > bb <- as.POSIXct("2001-09-24") > cc

Hello, I have the following loop for two data sets: diveData_2008 and diveData_2009. It uses two other data: diveCond_all and fishTable. The problem is at the point to identify the dive_id for the given index (index is timestamp). It keeps on saying for the1st loop Error in fishReport$dive_id[i] <- dive_id : replacement has length zero for the 2nd loop Error in fishReport$dive_id[i + j] <-

I'm trying to produce a series of powers of a number as follows: |> 0.05^0:5 [1] 1 2 3 4 5 This is not the result I expected. I guess some kind of coercion happened, since, |> class(0.05^0:5) [1] "integer" Could anyone explain me what is happening here? Thanks, -Sergio.

Hi, I don't understand the following. When I create a small artificial set of date information in class POSIXct, I can calculate the mean and the median: a = as.POSIXct(Sys.time()) a = a + 60*0:10; a [1] "2009-03-10 11:30:16 EDT" "2009-03-10 11:31:16 EDT" "2009-03-10 11:32:16 EDT" [4] "2009-03-10 11:33:16 EDT" "2009-03-10 11:34:16

Hi, Is there any official way to determine the colClasses of a data.frame? Why has POSIXct such a strange class structure? Why is colClasses "ordered" not allowed (and doesn't work)? Background ========== I am writing a chunked csv reader that provides the functionality of read.table for large files (in the next version of package ff). In chunked reading, one wants to learn the

Please see example code below. I have a vector ("mydata") of length 10. "mydata" can have various formats (e.g. numeric, text, POSIXct, etc) I use the matrix and data.frame functions to convert "mydata" to a dataframe ("mydf") of 2 columns and 5 rows. What is a "good" way to ensure that the format is retained when I create the

Hi All, I am attempting to work with some data from loggers. I have read in a .csv exported from MS Access that already has my dates and times (in 24 clock format), (with StringsAsFactors=FALSE). > head(tdata) LogData date time 1 77.16 2008/04/24 02:00 2 61.78 2008/04/24 04:00 3 75.44 2008/04/24 06:00 4 89.43 2008/04/24

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

What is the recommended way to convert/coerce and integer to a POSIXct please? d <- as.POSIXct(Sys.Date()) i <- as.integer(d) as.POSIXct(i) Error in as.POSIXct.default(i) : do not know how to convert 'i' to class "POSIXlt" This appears to be the behaviour in 2.3.1 and 2.4.0 on windows XP. I have tried searching on this and found as.Date.integer in package zoo which

I am trying to coerce a data frame column from character to datetime using strptime but keep getting an error because the length of the coerced object is always 9. What am I doing wrong here: ................................................................. > ds <- cbind(1:2, c("02/27/92 23:03:20", "02/27/92 22:29:56")); ds [,1] [,2] [1,]

The return value of Sys.time() today with a timezone of US/Eastern is unchanged between 4.0.3-patched and devel, but on devel the following test fails all.equal(x, as.POSIXlt(x)) with x = Sys.time() This means that devel does not complete make tests (failure on tests/reg-tests-2.R) It is entirely possible that it is an error on my end, I use export TZ="US/Eastern" but I have been

Hello, I searched the archives but could not come to a solution. I have to two columns of information t_start_cdt looks like: > t_start_cdt[1:4] [1] "2003-07-09 11:02:25" "2003-07-09 11:10:25" "2003-07-09 11:30:25" [4] "2003-07-09 12:00:25" > class(t_start_cdt) [1] "POSIXt" "POSIXlt" t_end_cdt looks like: > t_end_cdt[1:4]