Displaying 20 results from an estimated 4000 matches similar to: "cut.Date functionality for chron date/time objects"
2006 Jul 14
2
chron vs. POSIX
Hi,
One of the big decisions when writing code is how to handle dates and
times. Gabor Grothendieck provided an excellent overview of the issue in
his R News 4/1 (2004) article, and many users and developers are probably
using it as a guide. The proposed guideline is to use the simplest class
required; as Gabor put it "use Date if possible, otherwise use chron, and
otherwise use
2005 May 17
2
cumsum on chron objects
Hi,
Is there some alternative to cumsum for chron objects? I have data frames
that contain some chron objects that look like this:
DateTime
13/10/03 12:30:35
NA
NA
NA
15/10/03 16:30:05
NA
NA
...
and I've been trying to replace the NA's so that a date/time sequence is
created starting with the preceding available value. Because the number of
rows with NA's following each available
2006 Jun 12
1
cumulative time durations of specified periods (chron)
Hi,
Say we have two chron vectors representing start and end date/times of an
event, respectively:
R> (xfrom <- chron(seq(1.25, 11, 3.25)))
[1] (01/02/70 06:00:00) (01/05/70 12:00:00) (01/08/70 18:00:00)
[4] (01/12/70 00:00:00)
R> (xto <- chron(as.numeric(xfrom) + seq(1.5, 2.25, 0.25)))
[1] (01/03/70 18:00:00) (01/07/70 06:00:00) (01/10/70 18:00:00)
[4] (01/14/70 06:00:00)
and we
2005 Nov 30
3
setting R_LIBS
Hello,
I'm adding a private library tree in my home directory by adding this to
my ~/.Renviron:
R_LIBS="~/R/library:${R_LIBS}"
so that once in R:
R> cat(Sys.getenv("R_LIBS"), "\n")
~/R/library:/usr/local/lib/R/site-library:/usr/lib/R/site-library:/usr/lib/R/library
Is this the best way to proceed?
Cheers,
--
Sebastian P. Luque
2006 Jul 07
2
dotplot (lattice) with panel.segments and groups
Hi,
The following produces almost exactly what I needed. The problems are
that the 'panel.dotplot' call (commented) generates the error 'Error in
NextMethod("[") : argument "subscripts" is missing, with no default'. The
other problem is that the colors alternate between the levels of the 'site'
variable, rather than 'year'.
barley$yield2
2011 Aug 30
3
having trouble extracting week from chron object
Running R 2.13.1 on Windows XP.
I would like to get week of the year (1-52) for each date.
library(chron)
dts <- dates(c("02/27/92", "02/27/92", "01/14/92","02/28/92", "02/01/92"))
dts
dts.chron <- as.chron(dts)
dts.chron
class(dts.chron)
# all of these component extractions work:
months(dts.chron)
weekdays(dts.chron)
years(dts.chron)
2002 Oct 18
1
Chron problem with R 1.6.0 (PR#2181)
Full_Name: Rick Bilonick
Version: 1.6.0
OS: Linux (RH 7.1)
Submission from: (NULL) (12.4.226.1)
Hi. I'm using Red Hat 7.1 Linux (Intel 586). I installed the 1.6.0 rpm. No
problems were reported. When I tried to load the chron library:
Error in dyn.load(x, as.logical(local), as.logical(now)) :
unable to load shared library "/usr/lib/R/library/chron/libs/chron.so":
2008 Aug 01
1
chron objects: input/output
Hi list, I have some questions regarding
1) conversion of date + time characters to chron
2) formatting chron object printing
Regarding (1), Gabor's Rnews 2004 4/1 article has been indispensible,
but I often work with files where dates and times are contained in a
single field. In this case, I would like to control input/output of
chron objects when each observation of date and time is
2012 Jun 15
2
time zones and the chron to POSIXct conversion
Hey R folks,
i found some strange (to me) behaviour with chron to POSIXct conversion.
The two lines of code result in two different results, on ewith the
correct time zone, one without:
library(chron)
as.POSIXct(chron('12/12/2000'), tz = 'UTC')
as.POSIXlt(chron('12/12/2000'), tz = 'UTC')
Only the code below would give me a POSIXct object with the correct time
2005 Jun 01
2
problem with chron scales in lattice
I can't get the scales parameter in xyplot of lattice to work as I
expected. I'm using R-2.1.0 and lattice 0.11-8. There should be year
labels from 1992 to 2004 for the x axis in the plot below, but instead
only a few of them appear, and in the wrong spots, as if the coordinate
system has changed after finishing with the panel function.
library(chron)
library(lattice)
# vertical grid
2005 Nov 16
1
COM dates (was origin and "origin<-" in chron)
I was just looking for an easy way to convert between COM datetime and
chron datetime (both ways.)
I found examples on the list, but they involved origin.
Does anyone have functions for converting COM datetime <-> chron
datetimethat work "safely"?
David L. Reiner
> -----Original Message-----
> From: Gabor Grothendieck [mailto:ggrothendieck@gmail.com]
>
2011 Sep 16
1
Mystified - comparing chron times
I have two local variables: startTime and expectedStartTime. Both are chron
related objects.
When I look at the class for the objects I can see they are of class
"times".
When I print them to the console, they both read: "09:30:00"
When I print them as.numeric(), they both read: 0.3958333
When I try and compare them: (as.numeric(startTime) ==
as.numeric(expectedStartTime)) it
2012 Nov 27
2
Some questions about chron package..
Hello,
I have questions while reviewing "chron" package(e.g.,chron.R).
1. What is the differences between 3 kinds of function definition ?
1) "name" <- function(...
2) 'name' <- function(...
3) name <- function(...
Do you know Why author used various kinds of definitions ?
Is there no functional differences between them ?
2. I
2006 Nov 20
1
a little help needed plotting chron object
Hello there,
Using R 2.4.0 on Solaris (Unix):
I am trying to control the X axis range on a simple time of day plot.
I made a test program (below) that gets file time stamp information from
the files in the directory where R starts. The goal of the test program is
to plot the time of day of file creation on an x axis that spans a
user-specified range (like 12:00:00 to 15:00:00).
If I allow
2008 Dec 09
1
chron - when seconds data not included
I have date and time data which looks like this:
[,1] [,2]
[1,] "7/1/08" "9:19"
[2,] "7/1/08" "9:58"
[3,] "7/7/08" "15:47"
[4,] "7/8/08" "10:03"
[5,] "7/8/08" "10:32"
[6,] "7/8/08" "15:22"
[7,] "7/8/08" "15:27"
[8,] "7/8/08"
2006 Sep 20
1
hours() in 'chron': output != input
I encountered surprising (to me, at least) behavior while using 'hours()'
in package 'chron.' I will be grateful if someone can point out my error
or provide an explanation and intuitive solution (I suppose I could
convert chron to a character vector and use substring, but I deal mostly
with newbies and kludgy approaches don't inspire much confidence).
I used 2.3.0 to
2000 Feb 16
1
chron and mysql
R 0.90.1
chron 2.2-2
MySQL 3.22.30
Attempts to create a chron object fail when using date and time data
from a mysql database. It appears that chron does not like 4 digit
years. Is this the problem?
my data look like:
> c.time[1:10,]
Date Time
1 2000-02-14 10:15:02
2 2000-02-14 10:17:03
3 2000-02-14 10:18:03
4 2000-02-14 10:19:03
5 2000-02-14 10:20:04
6 2000-02-14
2006 Jun 23
2
problem with hist() for 'times' objects from 'chron' package
Hello dear useRs and wizaRds,
I encountered the following problem using the hist() method for the
'times' classes
from package 'chron'. You should be able to recreate it using the code:
library(chron)
# pasted from chron help file (?chron)
dts <- dates(c("02/27/92", "02/27/92", "01/14/92", "02/28/92",
"02/01/92"))
class(dts)
2013 May 01
3
Chron format question h:m not working
R 2.12.2 on Scientific Linux 6.4
#works
chron(times.="15:00:00", format=c(times="h:m:s"))
#doesn't work
chron(times.="15:00", format=c(times="h:m"))
From chron Manual:
The times format can be any permutation of "h", "m", and "s" separated
by any one non-special character. The default is "h:m:s".
what am I
2011 Jul 28
3
how to shift a chron timestamp by 6:30 hours
Dear help list,
I have a timestamp in as a chron object:
> (x <- chron(dates = c("12/02/11", "22/11/11"),
+ times = c("07:30:00", "04:00:00"),
+ format = c(dates = "d/m/y", times = "h:m:s")))
[1] (12/02/11 07:30:00) (22/11/11 04:00:00)
Now I want to shift the timestamp by 06:30 (hh:mm) backwards, to get