Displaying 20 results from an estimated 20000 matches similar to: "how to calculate time interval between dates"
2009 Jul 21
4
how to transform m/d/yyyy to yyyymmdd?
Hello,
I have a set of data that has a Date column looks like this:
12/9/2007
12/16/2007
1/1/2008
1/3/2008
1/12/2008
etc.
I'd like the date to look something like the follow (so that I could sort by
date easily).
20071209
20071216
20080101
20080103
20080112
How to do it? Thank you very much
Julia
--
View this message in context:
2008 Sep 11
3
Calculate mean/var by ID
Hello,
I have a data set that looks like this.
ID value
111 5
111 6
111 2
178 7
178 3
138 3
138 8
138 7
138 6
.
.
.
I'd like to calculate the mean and var for each object identified by the ID.
I can in theory just loop through the whole thing..., but is there a easier
way/command which let me calculate the mean/var by ID?
Thanks,
Julia
--
View this
2008 Oct 10
4
how to store lme/lmer fit result
Dear R users,
I am building a hierarchical model on a large data set. It can take quite
some time to finish one fit, I was just wondering whether it is possible to
store the fit object (the result) to a file for later (offline) analysis.
thanks
Julia
--
View this message in context: http://www.nabble.com/how-to-store-lme-lmer-fit-result-tp19910951p19910951.html
Sent from the R help mailing
2009 Jun 17
3
how to read in only some columns of a data file
Hello,
I have a data file (.csv) that has a size of about 2.6 GB. I am not able to
read in the whole data set because of the memory limit. I actually only need
some columns (3 columns) of the data set, is there a way to read in
specified columns?
I am using windows.
Thanks,
Julia
--
View this message in context:
2009 Jan 12
3
roll weekly data to monthly level
Dear R users:
I have a data set that looks something like this:
ID time y
1 2/01/2008 4
1 2/09/2008 12
1 9/01/2008 8
2 1/06/2008 3
2 3/01/2008 4
2 3/09/2008 9
2 6/03/2008 4
3 1/02/2008 3
3 1/10/2008 8
3 2/02/2008 7
3 2/10/2008 3
I'd like to sum up the weekly data to the monthly level, so that it looks
something
2009 Jun 01
2
how to checking whether elements of a vector changed or not.
Hello,
I have a vector:
x <- c("A", "A", "A", "B", "A", "A", "C")
I'd like to compare each of elements of vector x from its previous element
(except for the 1st element which does not have previous element). So I'd
like to get a vector y (of same length) that looks something like
(0, 0, 0, 1, 1, 0, 1) or
(F, F, F,
2008 Sep 30
1
Adding legends to a plot
Hello,
I have a time series plot drawn using 3 different colored lines, each line
corresponds to different category group. I'd like to put legends on the
plot. I am using "legend" to do this, however, I can either specify lty or
col in legend. Will I be able to do the following in the legend box: a solid
black line then g1, a solid red line then g2, a solid blue line then g3?
2008 Oct 30
1
How to increase iteration limit for lmer()?
Dear R users:
I am running lmer(), and I had the following warning message:
"In mer_finalize(ans): iteration limit reached without convergence (9)
What is the default limit for lmer()? And how do I increase the limit?
Many thanks,
Julia
--
View this message in context: http://www.nabble.com/How-to-increase-iteration-limit-for-lmer%28%29--tp20252974p20252974.html
Sent from the R help
2009 Feb 11
3
two scatter plots in one
Dear R users,
I need to compare two scatter plots,
plot(x1, y1)
plot(x2, y2)
and would like to plot them in the same figure. How do I do it?
Thank you.
--
View this message in context: http://www.nabble.com/two-scatter-plots-in-one-tp21963375p21963375.html
Sent from the R help mailing list archive at Nabble.com.
2005 Mar 18
1
RE: problem with Dates
It seems that you have load the "survival" package
date.mdy is a function from this one.
In this function the "origin" of the time is the first day of 1970
in the base package the origin is the first day of 1960
it's very curious...
Benjamin Esterni
France
From: "Vegard Andersen" <vegard.andersen@ism.uit.no>
Subject: [R] Date conversion problem using
2010 Jan 27
2
plotting the coordinates versus dates
Hello!
I have a dataset with the dates and positions - Lat and Long columns
How do I make a scatter plot?
Do I have to cbind to combine the Lat and Long columns?
Any suggestions will be much appreciated!
Thank you
Julia
[[alternative HTML version deleted]]
2005 Sep 26
3
dates are shown as X15.Feb.03
Why is R recognizing dates like this?
Chris Buddenhagen, Botany Department, Charles Darwin Research Station, Santa
Cruz,Galapagos. Mail: Charles Darwin Foundation, Casilla 17-01-3891 Avenida
6 de Diciembre N36-109 y Pasaje California Quito, ECUADOR
______________________________________________________________________
EL CONTENIDO DE ESTE MENSAJE ES DE ABSOLUTA RESPONSABILIDAD DEL
2008 Oct 16
1
increase memory limit in R
Dear R users,
I am running lmer() and having memory problem: "reached total allocation of
1535Mb".
The lmer() function was successful (no errors or warnings). However when I
do "summary(fit.lmer), I got this "Error: cannot allocate vector of size
19.5 Mb). I used memory.size() and got 1880. I used memory.limit(2500) to
increase the memory size to 2500Mb, however I still get
2009 May 29
1
frequence of patterns in a vector
Dear R users,
Suppose I have a vector that consists of characters like ABC, A02, RCA,
etc., and there are about 700 of possible characters. For example,
x <- c("ABC", "ABC", "ABC", "A02", "ABC", "RCA", "ABC", "ABC")
I'd like to get a frequency matrix that looks something like this:
ABC 6
A02 1
RCA 1
I
2009 Sep 24
1
multinormial runs tests?
Dear R users,
I would like to test the randomness in a series of N values (N>=2). I know
that runs.test works for dichotomous factor only:
x <- rep(c(1,2), 50)
runs.test(factor(x))
However it doesn't work for series that can take any N values (N>2):
x <- rep(c(1,2,5,4),50)
runs.test(factor(x))
Error in runs.test(factor(x)) : x does not contain dichotomous data
Are there any R
2008 Oct 08
2
detect repeated number in a vector
Dear R users,
I have this vector that consists numeric numbers. Is there a command that
detects the repeated numbers in a vector and returns the index of the
repeated numbers (or the actual numbers)? For example, v <- c(3,4,5,7,4).
The command would return me index 2 and 5 (or the repeated number, 4).
Thank you very much,
Julia
--
View this message in context:
2006 Jul 07
3
calculate number of months difference between two dates
hi,
Is there an easy way of calculating the difference in months between two
dates in a controller.
thanks
--
Posted via http://www.ruby-forum.com/.
2007 Sep 24
2
Calculate difference between dates in years
Hello,
I would like to be able to calculate the age of someone at a particular
date. Both dates are date objects. Here is what I have come up with:
floor(as.numeric(sampleInfo$Date.of.DIAGNOSIS-sampleInfo$Date.of.birth)/365.25)
Is this the best approach? or is there an inbuilt function? I have
looked at difftime but that does not seem to allow output in years.
Many thanks
Dan
--
2008 Aug 11
1
A zoo question / problem
Hi
I'm having a problem using the zoo library and I can't see what I'm
doing wrong. For example setting up the data
> t1 = zoo (matrix (1:12, nrow = 3), order.by = as.Date
(c("2008-08-01","2008-08-02","2008-08-03")))
> colnames (t1) = c ("A", "B", "C", "D")
> t2 = zoo (matrix (1:12, nrow = 3), order.by =
2008 Feb 07
1
Calculate the difference between dates
Dear list,
I have two data columns (part of big data frame) containing dates presenting the dates when
two measurements (M1 and M2) were taken. The data consists of 73 individuals divided
in different groups. Each group was examined at different time points (see M1 date),but
the measurements (M1 and M2) within each group should be taken in the same day but due
to some practical issues,