Displaying 20 results from an estimated 20000 matches similar to: "select observations from longitudinal data"
2009 Jan 18
2
select observations from longitudinal data set
I have the following longitudinal data:
id time y
1 1 10
1 2 12
1 3 15
1 6 18
2 1 8
2 3 9
2 4 11
2 5 12
3 1 8
3 4 16
4 1 9
4 5 13
5 1 7
5 2 9
5 6 11
....
I want to select the observations at time 4. if the observation at time 4 is
missing, then i want to slect the observation at time 3. if the observation
at time 3 is also missing, then i want to select observation at time 5.
otherwise i will
2007 Jan 27
2
unequal number of observations for longitudinal data
i have a large longitudinal data set. The number of observations for each
subject is not the same across the sample. The largest number of a subject
is 5 and the smallest number is 1.
now i want to make each subject to have the same number of observations by
filling zero, e.g., my original sample is
id x
001 10
001 30
001 20
002 10
002 20
002 40
002 80
002 70
003 20
003 40
004 ......
now i wish
2007 Oct 28
1
gam for longitudinal data?
I used gam for data analysis a lot. Is it possible to use gam to analyze
longitudinal data? I mean, besides the working independence assumption, can
i specify other more reasonable covariance structure in gam?
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2007 Jan 27
3
how to handle a longitudinal data
i have a data set with repeated measures on same people, structure like
below:
id x1 x2 ...
001 10 20 ...
001 8 45 ...
001 4 2 ...
002 ....
002 ...
002 ....
002 ....
003 ....
.......
what is the easist way to show how many observations for each subject id?
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2013 Feb 23
5
Selecting First Incidence from Longitudinal Data
I have a longitudinal competing risk data of the form:
ID COMPL SEX HEREDITY
1 0 1 2
1 0 1 2
1 3 1 2
2 0 0 1
2 1 0 1
2 2 0 1
2 2 0 1
3 0 0 1
3 0 0 1
3 0 0 1
3 0 0 1
3 2 0 1
4 0 1 2
4 0 1
2010 Sep 07
2
some questions about longitudinal study with baseline
Hi all,
I asked this before the holiday, didn't get any response. So would like to
resend the message, hope to get any fresh attention. Since this is not purely
lme technical question, so I also cc-ed R general mailing list, hope to get some
suggestions from there as well.
I asked some questions on how to analyze longitudinal study with only 2 time
points (baseline and a follow-up)
2010 Apr 22
4
how to select the first observation only?
Dear r-helpers,
I have a very simple question. Suppose my data is like
id=c(rep(1,2),rep(2,2))
b=c(2,3,4,5)
m=cbind(id,b)
> m
id b
[1,] 1 2
[2,] 1 3
[3,] 2 4
[4,] 2 5
I wish to select the first observation for each id. That is, I want to
quickly select two rows:
id b
1 2
2 4
only. how should i do this?
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2010 Sep 07
2
Plotting longitudinal data
Hello,
Hope that someone could help me plotting longitudinal data below:
7213 3333330001 0.8300 13.05.09 1
1 3333330001 0.8700 09.02.05 NULL
4797 3333330001 0.7700 21.03.07 NULL
2399 3333330001 0.7800 12.04.06 NULL
2400 3333330002 NULL 27.03.06 NULL
7230 3333330002 0.8200 14.05.09 0
2 3333330002 0.8400 09.02.05 NULL
4798 3333330002 0.8700 20.03.07 0
4799 3333330003 0.9000 20.03.07 13
2401
2011 Mar 24
3
Longitudinal categorical response data
Dear List,
I have some longitudinal data, each patient was followed at times 0, 12, 16, 24 weeks and measure severity of a illness (0-worse, 1-same, 2-better). So, longitudinal response is categorical. I was wondering whether lmer in R can fit a model for this type of data. If so, how we code? Or any other function in R that can fit this type of longitudinal data? Any suggestion would be
2011 Feb 10
1
Longitudinal Weights in PLM package
Hi all,
I a semi-beginner with R and I am working with the plm package to examine a
longitudinal dataset. Each individual in this dataset has a longitudinal
weight for the probability that he or she remains in the sample.
Unfortunately, I have not found an argument to use weights in the plm
function? I tried ?weights=? like in standard lm or in nlme or lm4 but it
does not work. I asked the
2008 Jul 25
1
Selecting the first measurement only from a longitudinal sequence
Dear R-help mailing list,
I have this problem, I have a joint longitudinal and survival data of the form say
ID Time Failuretime Censoringind longitudinalmeasure
1 0 35 0 123
1 10 35 0 120
1 25 35 1 123
2 0 23 0 100
2 10 23
2013 Jan 18
3
longitudinal study
Hello R user,
I have a data set from a longitudinal study ( sample below) where
subjects are followed over time. Second column (status) contains info
about if subject is dead or still in the study and third column is
time measured in the week. Here is what I need: if status is not dead
or unknown take the last week, if status is dead or unknown I need to
have corresponding week.
Desired resulst:
2007 Jul 17
2
xyplot for longitudinal data
Dear R-help subscribers,
I use xyplot to plot longitudinal data as follows:
score<-runif(100,-4,5)
group<-sample(1:4,100,rep=T)
subject<-rep(1:25,4)
age<-rep(runif(4,1,40),25)
df<-data.frame(score,group,age,subject)
xyplot(score~age|group, group=subject,
panel=function(...){
panel.loess(...,lwd=4)
panel.superpose(...)}
,data=df)
this produced a plot with four panels one for each
2008 Nov 24
3
select a subset
I have the complete data like
id time censor
1 10 0
1 20 0
1 30 0
2 10 0
2 20 1
2 30 0
2 40 0
3 10 0
3 20 0
3 30 1
....
for id 1, i want to select the last row since all censor indicator is 0; for
id 2, i want to select the row where censor ==1; for id 3, i also want to
select the row where censor==1. So if there is a 1 for censor, then I want
to select such a row, otherwise I want to select the
2011 Mar 21
1
Sample size of longitudinal and skewed data
Hi all:
I have a question about the sample size calculation.
It's a pilot study,which includes 2 groups(low,high),3 time point(3,6,9
monthes).Each person has 3 results which according to the
3 time points.So it's a longitudinal study.
I want to calculate the minimum sample size from the pilot study, but can't
find the solution since the data is highly skewed and
it's a
2005 Jan 20
3
Constructing Matrices
Dear List:
I am working to construct a matrix of a particular form. For the most
part, developing the matrix is simple and is built as follows:
vl.mat<-matrix(c(0,0,0,0,0,64,0,0,0,0,64,0,0,0,0,64),nc=4)
Now to expand this matrix to be block-diagonal, I do the following:
sample.size <- 100 # number of individual students
I<- diag(sample.size)
bd.mat<-kronecker(I,vl.mat)
This
2008 Aug 07
2
help with longitudinal data plot
Dear R Help,
I am attempting to make a plot of longitudinal data, a sample data
frame of which is shown below.
I'd like to show all of the subjects in the same plot, with a set of
connecting line segments for each subject. 'age' would be the x-axis
and 'score' would be the y-axis.
subject age score
1 10123 12 51.06
2 10123 14 50.00
3 10123 15 62.22
4
2010 Mar 23
3
barplot (stacked)
Dear all,
I want to draw a barplot with the following data:
[,1] [,2] [,3] [,4] [,5] [,6] [,7]
[,8] [,9]
[1,] 110.0675 118.4167 117.16 109.735416 101.6312 104.0312 101.8263
99.38541670 114.2613
[2,] 0.0000 0.0000 0.00 1.658333 0.0000 0.6250 0.0000
0.05208333 0.0000
[,10] [,11] [,12] [,13] [,14] [,15] [,16]
2008 Mar 12
1
[follow-up] "Longitudinal" with binary covariates and outcome
Hi again!
Following up my previous posting below (to which no response
as yet), I have located a report which situates this type
of question in a longitudinal modelling context.
http://www4.stat.ncsu.edu/~dzhang2/paper/glm.ps
Generalized Linear Models with Longitudinal Covariates
Daowen Zhang & Xihong Lin
(This work seems to originally date from around 1999).
They consider an outcome Y,
2005 May 26
1
longitudinal survey data
Dear R-Users!
Is there a possibility in R to do analyze longitudinal survey data (repeated
measures in a survey)? I know that for longitudinal data I can use lme() to
incorporate the correlation structure within individual and I know that there is
the package survey for analyzing survey data. How can I combine both? I am
trying to calculate design-based estimates. However, if I use svyglm() from