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,

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

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 >

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