Displaying 20 results from an estimated 5000 matches similar to: "date"
2008 Apr 09
2
fuzzy merge
Hi,
I would like to merge two data frames. It is just that I want the merging to be done with some kind of a fuzzy criterion. Let me explain.
My first data frame looks like this :
ID1                     time1                                dt            
1                        2008-01-02 13:11                10
2                        2008-01-02 14:20                20
3                      
2011 Aug 14
2
Trouble: Time Difference with difftime
Hello all!!!
I want to measure the duration of events (given a start and an end time).
The catch is that I require the output in calender days. This means:
02-Jan-2011 00:01:00  minus 01-Jan-2011 23:59:00 should be 1 day (although
the real time difference is only 2 minutes)
My data is the following
head(episode.ct)
[1] "2009-07-13 13:37:20 CEST" "2009-07-14 07:29:20 CEST"
2010 Nov 15
3
merge two dataset and replace missing by 0
Hi r users,
I have two data sets (X1, X2). For example,
time1<-c( 0,   8,  15,  22,  43,  64,  85, 106, 127, 148, 169, 190 ,211 )
outpue1<-c(171 ,164 ,150 ,141 ,109 , 73 , 47  ,26  ,15  ,12   ,6   ,2   ,1 )
X1<-cbind(time1,outpue1)
time2<-c( 0   ,8  ,15 , 22  ,43 , 64  ,85 ,106 ,148)
output2<-c( 5   ,5   ,4   ,5   ,5   ,4   ,1   ,2 ,  1 )
X2<-cbind(time2,output2)
I want to
2007 Jan 19
4
Newbie question: Statistical functions (e.g., mean, sd) in a "transform" statement?
Greetings listeRs - 
 
Given a data frame such as 
 
times
       time1    time2     time3    time4
1  70.408543 48.92378  7.399605 95.93050
2  17.231940 27.48530 82.962916 10.20619
3  20.279220 10.33575 66.209290 30.71846
4         NA 53.31993 12.398237 35.65782
5   9.295965       NA 48.929201       NA
6  63.966518 42.16304  1.777342       NA
 
one can use "transform" to
2010 Jan 12
0
Wishlist: Function 'difftime' to honor 'tzone' attribute (PR#14182)
Full_Name: Suharto Anggono
Version: 2.8.1
OS: Windows
Submission from: (NULL) (125.165.84.118)
PR#14076 inspired me to write this.
> t1 <- as.POSIXct("1970-01-01 00:00:00", tz="GMT")
> t2 <- as.POSIXlt("1970-01-01 00:00:00", tz="GMT")
> t1 - t2
Time difference of 7 hours
Above, t1 and t2 represent the same time in the same specified
2011 Jul 19
1
Measuring and comparing .C and .Call overhead
Further pursuing my curiosity to measure the efficiency of R/C++ interface, I
conducted a simple matrix-vector multiplication test using .C and .Call
functions in R. In each case, I measured the execution time in R, as well as
inside the C++ function. Subtracting the two, I came up with a measure of
overhead associated with each call. I assume that this overhead would be
non-existent of the entire
2010 Jan 16
2
Extracing only Unique Rows based on only 1 Column
To Whomever is Interested,
I have spent several days searching the web, help files, the R wiki  
and the archives of this mailing list for a solution to this problem,  
but nonetheless I apologize in advance if I have missed something  
obvious.
The problem is this; I have a 5-column data frame with about 4.2  
million rows, and want to create a new (and hopefully much smaller)  
data frame that
2011 Mar 18
1
median survival time from survfit
Hello,
I am trying to compute the mdeian of the survival time from the function
survfit:
> fit <- survfit(Surv(time, status) ~ 1)
> fit
Call: survfit(formula = Surv(time, status) ~ 1)
records   n.max n.start  events  median 0.95LCL 0.95UCL
    111     111     111      20      NA      NA      NA
The results is NA? the fit$surv gives values between 1 and 0.749! Am I doing
this correct?
2009 Sep 11
1
What determines the unit of POSIXct differences?
Dear All,
what determines if a difference between POSIXct objects gets 
expressed in days or seconds?
In the following example, it's sometimes seconds, sometimes days.
as.POSIXct('2009-09-01') - as.POSIXct(NA)
Time difference of NA secs
c(as.POSIXct('2009-09-01'), as.POSIXct(NA)) -
   c(as.POSIXct('2009-09-01'), as.POSIXct('2009-08-31'))
Time differences in
2007 Dec 16
4
improving a bar graph
Hello,
Below is the code for a basic bar graph. I was seeking advice 
regarding the following:
(a)  For each time period there are values from 16 people. How I can 
change the colour value so that each person has a different colour, 
which recurs across each of the three graphs/tie epriods?
(b) I have seen much more sophisticated examples using lattice (e.g 
each person has a separate
2012 Nov 30
1
help on "stacking" matrices up
Dear All,
 
#I have the following code
 
Dose<-1000
Tinf <-0.5
INTERVAL <-8
TIME8 <-matrix(c((0*INTERVAL):(1*INTERVAL)))
TIME7 <-matrix(c((0*INTERVAL):(2*INTERVAL)))
TIME6 <-matrix(c((0*INTERVAL):(3*INTERVAL)))
TIME5 <-matrix(c((0*INTERVAL):(4*INTERVAL)))
TIME4 <-matrix(c((0*INTERVAL):(5*INTERVAL)))
TIME3 <-matrix(c((0*INTERVAL):(6*INTERVAL)))
TIME2
2011 Sep 26
3
survival analysis: interval censored data
hello:
my data looks like:
time1  time2   event  catagoria
2004    2006        1            C
2004    2005        0            C
2005    2010        1            E
2007    2009        1            C
2006    2007        0            E
2008    2010        0            C
2008    2010        1            E
...
and the census interval is 1 year
I have tried  this 
2013 Mar 21
1
All unique combinations
Dear all,
I would like to have all unique combinations in the following matrix
TimeIndex<- rbind (c(1,"Week_of_21_07-29_03"), 
          c(2,"Thursday_21_03"),
          c(3,"Friday_22_03"),
          c(4,"Saturday_23_03"),
          c(5,"Sunday_24_03"),
          c(6,"Monday_25_03"),
          c(7,"Tuesday_26_03"),
       
2010 Feb 23
3
difference between date and times
Hi,
 
I have date and time in a format like this: " 2007-02-21 05:19:00".
Do you which function i can use to derterminate the difference in time between this value and an other one.
For exemple:
 
this one : 2007-02-21 05:19:00
and this one : 2007-02-20 14:21:53
 
Thanks a lot,
Karine H.
 		 	   		  
_________________________________________________________________
2004 Aug 05
1
Post-hoc t-tests in 2-way repeated measure ANOVA
Hi all
I am running a 2-way repeated measure anova with 1 between-subjects 
factor (Group=treatment, control), and 1 within-subject factor (Time of 
measurement: time1, time2).  I extract the results of the anova with:
summary(aov(effect ~ Group*Time + Error=Subj/Time, data=mydata))
Now, this must be clearly a dumb question, but how can I quickly extract 
in R all the post-hoc t-tests for the
2011 Nov 11
1
How to compute time interval?
time1 = 2008-03-09
time2 = 2010-9-10
How to compute how many years between time1 and time2?
Thanks!
best
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2009 Jan 27
2
Can I create a timeDate object using only year and week of the year values?
For a model I am working on, I have samples organized by year and week of
the year.  For this model, the data (year and week) comes from the basic
sample data, but I require a value representing the amount of time since the
sample was taken (actually, for the purpose of the model, it is sufficient
to use the number of weeks from the middle of the sample week to the
present).
What I have found so
2007 Apr 10
1
Memory management
Hi all, I'm just curious how memory management works in R... I need to run an
optimization that keeps calling the same function with a large set of
parameters... so then I start to wonder if it's better if I attach the
variables first vs passing them in (coz that involves a lot of copying.. )
Thus, I do this
fn3 <- function(x, y, z, a, b, c){ sum(x, y, z, a, b, c) }
fn4 <-
2010 May 20
1
Strange behaviour when using diff with POSIXt and POSIXlt objects
Dear list,
I´m calculating time differences between series of time stamps and I noticed
something odd:
If I do this...
> time1=strptime("2009 05 31 22 57 00",format="%Y %m %d %H %M")
> time2=strptime("2009 05 31 23 07 00",format="%Y %m %d %H %M")
>
> diff(c(time1,time2),units="mins")
Time difference of 10 mins
.. I get the correct
2012 Mar 29
1
Adding duration (hh:mm:ss)\Converting factor column into duration class
Hi All,
I have a data frame:
              Time1    Time2
     1  176:46:10    41:48:06
     2  171:28:57    61:19:10
     3  178:25:15    34:05:35 
     4   74:04:20     25:01:55
     5  136:11:20    37:59:32
     6  138:17:17    30:22:27
     7  183:04:48    29:25:02
     8  179:35:01    19:29:44
> str(df)
'data.frame':   8 obs. of  2 variables:
 $ Time1: Factor w/ 583 levels