Displaying 20 results from an estimated 20000 matches similar to: "Time data"
2013 Apr 26
3
converting character matrix to POSIXct matrix
I thought this is a common question but rseek/google searches don't yield
any relevant hit.
I have a matrix of character strings, which are time stamps,
> time.m[1:5,1:5]
[,1] [,2] [,3] [,4] [,5]
[1,] "08:00:20.799" "08:00:20.799" "08:00:20.799" "08:00:20.799"
"08:00:20.799"
[2,]
2011 Jan 07
1
POSIXct issue
Hello I have trouble getting my original datetime back see below. I hope I
am missing something. Please help.
> tt <- as.POSIXct("2011-01-07 07:49:13", tz="EST")
> tt
[1] "2011-01-07 07:49:13 EST"
> ttn <- as.numeric(tt)
> ttn
[1] 1294404553
> tt <- as.POSIXct(ttn,origin='1970-01-01',tz="EST")
> tt
[1] "2011-01-07
2013 Mar 08
2
Zoo Data
Hi Jakob,
dat1<-read.table(text="
TIME, Value1, Value2
01.08.2011 02:30:00, 4.4, 4.7
01.09.2011 03:00:00, 4.2, 4.3
01.11.2011 01:00:00, 3.5, 4.3
01.12.2011 01:40:00, 3.4, 4.5
01.01.2012 02:00:00, 4.8, 5.3
01.02.2012 02:30:00, 4.9, 5.2
01.08.2012 02:30:00, 4.1, 4.7
01.12.2012 03:00:00, 4.7, 4.3
01.01.2013 01:00:00, 3, 4.3
01.01.2013 01:30:00, 3.8, 4.1
01.01.2013 02:00:00, 3.8,
2009 Oct 05
6
Date-Time-Stamp input method for user-specific formats
Date-Time-Stamp input method to correctly interpret user-specific
formats:coding is 90% there - based on exmple at
http://tolstoy.newcastle.edu.au/R/help/05/02/12003.html
...anyone got the last 10% please?
CONTEXT:
Data is received where one of the columns is a datetimestamp. At midnight,
the value represented as text in this column consists of just the date part,
e.g.
2010 Apr 16
6
bwplot puts the bars in the wrong place
Dear R-Help,
With the attached data set, I am still getting incorrect bwplots
> xyplot(gdf$tt~gdf$OnHour |gdf$Runway, data=gdf) # Is correct
> bwplot(gdf$tt~gdf$OnHour |gdf$Runway, data=gdf, horizontal=FALSE) #
Puts the boxes on the wrong x-axis values
# look especially at 0 and 3. How do I fix this?
What is happening?
Thanks,
Jim Rome
2009 May 20
2
Class for time of day?
What is the recommended class for time of day (independent of calendar
date)?
And what is the recommended way to get the time of day from a POSIXct
object? (Not a string representation, but a computable representation.)
I have looked in the man page for DateTimeClasses, in the Time Series
Analysis Task View and in Spector's Data Manipulation book but haven't found
these. Clearly I can
2009 Jan 04
1
POSIXct and chron issues with tz
Dear All-
I am trying to merge two data files - they have different date formats
and different times zones. I need to match up the date/time of the
datasets and then invoke a conditional statement, such as: if dataC$mph
is >= 12 then keep dataM$co23 for the corresponding time/date stamp.
snippets of data files:
*dataC.txt*
LST in mph Deg DegF DegF2 % volts Deg
2009 Oct 15
2
forwarded: bug (?) in cut.POSIXt with "breaks"=integer
From: Vitalie S. <vitosmail <at> rambler.ru>
Subject: Bug in cut.POSIXt
Newsgroups: gmane.comp.lang.r.general
Date: 2009-10-15 15:47:48 GMT (1 hour and 29 minutes ago)
Hello Everyone,
Before reporting decided to post here first:
tt <- structure(c(1254238817, 1254238859, 1254238969, 1254239080), class =
c("POSIXt",
2009 Jun 19
2
How to import timestamps from emails into R
I am analysing occurrences of a phenomenon by time, and each of these
timestamps taken from email headers represents one occurrence. (The last
number is the time zone.) I can easily change the format.
Sun, 14 Jun 2009 07:33:00 -0700
Sun, 14 Jun 2009 08:35:10 -0700
Sun, 14 Jun 2009 21:26:34 -0700
Mon, 15 Jun 2009 19:47:47 -0700
Wed, 17 Jun 2009 21:50:41 -0700
I've found documentation for a
2010 Jun 16
1
cut takes long time
The following cut command takes nearly 10 seconds on my machine even
though the length of input vector is only 6. I am running on Windows
Vista with C2D BLAS using R 2.11.1. Using the default BLAS and either
R 2.10.1 or "R version 2.12.0 Under development (unstable) (2010-05-31
r52164)" also gives me results in the 9-11 second range.
I would have expected it to take much less time.
2017 Dec 26
1
Time Series with Neural Networks
Hi,
I am would like to ask few questions.
I am trying to forecast hourly electricity prices by 24 hours ahead.
I have hourly data starting from 2015*12*18 to 2017-10-24
and I have defined the data as time series as written in the code below.
Then I am trying do neural network with 23 non-seasonal dummies and 1 seasonal dummy.
But I don?t know whether training set is enough.( Guess it is 50
2010 Feb 03
3
to convert a character string in time
hi,
I have my data time expressed in character string exple "5:20" (hour:min) and i want to convert these in times recognized by R. I have tried the POSIXct function:
balise07$Hour <- as.POSXIct(balise07$Hour)
but it didn't work.
Do you know why? Do you know how i can convert my string character in a real time?
Thanks
Karine HEERAH
Master 2 mention
2009 Apr 15
2
shift/lag when merge zoo
Hello alltogheter,
I have a little problem regarding merging to zoo series.
I want to merge two zoo series to reduce the timegaps between the stamps.
I use the following code:
data.test <-
as.POSIXct(seq(data.input01[1,1],data.input01[nrow(data.input01),1],900),tz="GMT")
data.troughput01 <- as.zoo(data.input01$V2)
index(data.troughput01) <-
2010 Apr 02
1
POSIX primer
I have not used POSIX classes previously and now have a need to use them. I have sports data with times of some athletes after different events. I need to perform some simple analyses using the times. I think I've figured out how to do this. I just want to confirm with others who have more experience that this is indeed the correct approach. If not, please suggest a more appropriate way.
2006 Aug 24
1
Using a 'for' loop : there should be a better way in R
I need to apply a yearly inflation factor to some
wages and supply some simple sums by work category. I
have gone at it with a brute force "for" loop approach
which seems okay as it is a small dataset. It looks
a bit inelegant and given all the warnings in the
Intro to R, etc, about using loops I wondered if
anyone could suggest something a bit simpler or more
efficent?
Example:
2008 Feb 08
2
When I cbind the POSIXct gets lost
I would like to create a new dataframe from the DateTime column of an
existing dataframe and a numeric vector. When I do cbind(x[,1], y) the
result is:
[1,] 1199370600 12.500
[2,] 1199371200 69.375
[3,] 1199371800 23.750
where the first column you see used to look like:
"2008-01-03 08:30:00 Central Standard Time"
"2008-01-03 08:40:00 Central Standard Time"
2009 Dec 01
4
median for time data
Hi everybody
How do I do to calculate the median and average of a colum of time data like
this: "8:50:10". I also need to plot the time difference between two colums
Thanks a lot
--
View this message in context: http://n4.nabble.com/median-for-time-data-tp932287p932287.html
Sent from the R help mailing list archive at Nabble.com.
2011 Jan 30
4
Extract time only from POSIXlt object
How can I extract only the time component from an POSIXlt object?
For example if I try the following it still returns both the date and
time...
>as.POSIXlt(tr.date[1])
[1] "2010-10-18 21:46:53"
>as.POSIXlt(tr.date[1],"%H:%M:%S")
[1] "2010-10-18 21:46:53"
round and trunc don't help... is there an "as.Time" equivalent to as.Date
?
Thanks,
2011 May 09
2
Round down to earliest hour or half hour
I have times and would like to round down to the earliest 30 minute
increment. For instance, a time of
2011-04-28 09:02:00
(the as.numeric value = 1303999320)
I would like it to be rounded down to:
2011-04-28 09:00:00
(the as.numeric value = 1303999200)
Any ideas of how to do this?
-----
In theory, practice and theory are the same. In practice, they are not - Albert Einstein
--
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2007 May 08
3
plot time series
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