similar to: Vectors of years, months, and days to dates?

I am curious if there is any way to list only variables or functions in current environment, rather than listing all objects? Thanks. -- Daehyok Shin (Peter) Geography Department Univ. of North Carolina-Chapel Hill

I am curious if there is any way to list only variables or functions in current environment, rather than listing all objects? Thanks. -- Daehyok Shin (Peter) Geography Department Univ. of North Carolina-Chapel Hill

I tried the code that Richard O'Keefe posted last week, to wit: library(chron) ymd.to.POSIXlt <- function (y, m, d) as.POSIXlt(chron(julian(y=y, x=m, d=d))) n <- 100000 y <- sample(1970:2004, n, replace=TRUE) m <- sample(1:12, n, replace=TRUE) d <- sample(1:28, n, replace=TRUE) system.time(ymd.to.POSIXlt(y, m, d)) [1] 8.78 0.10

Exactly where does R search for foo.R if I type source("foo.R")? Only from current working directory (same as getwd()), from all directories specified by e.g. $PATH? Thanks. Daehyok Shin

Exactly where does R search for foo.R if I type source("foo.R")? Only from current working directory (same as getwd()), from all directories specified by e.g. $PATH? Thanks. Daehyok Shin

What happens when I pass an array to a dynamically linked C routine? Is only its reference copied when an array is passed and returned? Or, is its whole content copied? In R extension manual, I found the following description. But, I can't know exactly which is true. "There can be up to 65 further arguments giving R objects to be passed to compiled code. Normally these are copied before

When I tried the following commands, I got a strange message. > x<-data.frame(y=c(1:10)) > plot(x$z) Error in xy.coords(x, y, xlabel, ylabel, log) : x and y lengths differ "The data frame, x, does not have a field named z." may be better user-friendly message for this kind of common error. Daehyok Shin

When I tried the following commands, I got a strange message. > x<-data.frame(y=c(1:10)) > plot(x$z) Error in xy.coords(x, y, xlabel, ylabel, log) : x and y lengths differ "The data frame, x, does not have a field named z." may be better user-friendly message for this kind of common error. Daehyok Shin

I try memory.size function to find out available memory size, but surprisingly R complains it can't find the function. ?memory.size also failed. Is it not in the base library? If so, why can't my R find it? I am using the binary 1.9.0 version for Mandrake 9.1. Thanks in advance. Daehyok Shin Terrestrial Hydrological Ecosystem Modellers Geography Department University of North

Hi! Is not there an standard R function to retrieve the day of the year (since 1st Jan of the same year)? I know I can make my own using julian, but find it weird that having days(), months() etc doy() does not exist as an standard function. Also, is the following not a bit inconsistent? > a <- chron("20100506",format="ymd") > a [1] 100506 > years(a) [1] 2010

I know this: > library(date) > x="1979-04-04" > try=as.date(x, "ymd") > print(try) [1] 4Apr79 and that `x' here has to be a string, e.g.: > x=1979-04-04 > print(x) [1] 1971 I'm stuck in reading from a file. I say: > A <- read.table(file="try") > print(A) V1 V2 1 1979-04-04

Hi all; I've already send a similar e-mail to the list and Prof. Brian Ripley answered me but my doubts remain unresolved. Thanks for the clarification, but perhaps I wasn't clear enough in posting my questions. I've got a postgres database which I read into R. The first column is Timestamp with timezone, and my data are already in UTC format. An 'printed' extract of R

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 am looking for a package to read and write NetCDF files. NetCDF package says it can only read, not write. Another package for the standard binary file format? Daehyok Shin

I am handling spatial data of huge volumes, so sensitive to the silent duplication of data in script programs. In the following R program, exactly when is the vector data deeply copied? Thanks in advance. 1 v <- 1:10000 2 z <- f(v) --------- function f ---------- 3 f <- function(x) { 4 y = x 5 y[10] = 1 6 xf = date.frame(x=x) 7 xf$x[10] = 1 8

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,

Dear R users, Given this data: x <- seq(1,100,1) dx <- as.POSIXct(x*900, origin="2007-06-01 00:00:00") dfx <- data.frame(dx) Now to play around for example: subset(dfx, dx > as.POSIXct("2007-06-01 16:00:00")) Ok. Now for some reason I want to extract the datapoints between hours 10:00:00 and 14:00:00, so I thought well: subset(dfx, dx >

I have some questions and comments on timezones. Problem 1. # get current time in current time zone > (now <- Sys.time()) [1] "2003-07-29 18:23:58 Eastern Daylight Time" # convert this to GMT > (now.gmt <- as.POSIXlt(now,tz="GMT")) [1] "2003-07-29 22:23:58 GMT" # take difference > now-now.gmt Time difference of -5 hours Note that the difference

Hi, how it's possible to extract the year and the number of days from Julian date. i'm little confused about the last two functions and ?years . EDATE comes from sqlQuery with as.is=T EDATE <- as.POSIXlt(datvears$ENROLLDAY) Many thanks, Christian > EDATE[1:5] [1] "2000-06-30 11:25:01" "2000-06-30 11:39:55" "2000-06-30 12:11:11" [4]

While installing my small package, I met a tricky problem. For clarity, let me explain it with the following simplified example. In ~/pkg/R/aclass.R, setClass("aclass", contains="bclass", representation(i="numeric")) In ~/pkg/R/bclass.R, setClass("bclass", representation(j="numeric")) After building a "pkg" package, the file