Displaying 20 results from an estimated 3000 matches similar to: "the Surv function"
2007 May 05
3
the ifelse function
Hi Everyone,
I think I found a problem with the ifelse function: If the condition
argument is NA, it treats it as true. Anyone agree or disagree with this?
Jen
--
Jennifer Dillon
Doctoral Student
Harvard Biostatistics
Room 414B, Building 1
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2005 Oct 25
3
making an inicator variable
Hello,
I am almost a total novice, and I am sure there must be an easy (and
basic) way to turn a variable of 1's and 2's into a variable of zeros
and ones. This is in a data frame, but if I could do it with vectors,
that's all I need.
Can someone tell me how?
Thanks so much,
Jen
2009 May 15
1
Function Surv and interpretation
Dear everyone,
My question involves the use of the survival object.
We can have
Surv(time,time2,event, type=, origin = 0) (1)
As detailed on p.65 of:
http://cran.r-project.org/web/packages/survival/survival.pdf
My data (used in my study) is 'right censored' i.e. my variable corresponding to 'event' indicates whether a person is alive (0) or dead (1) at date last seen
2006 Sep 28
10
What does "State group failed" mean?
One one of my new vmware guests... puppetd -v spits out a bunch of
err & warnings about "State group failed"... what does this mean?
<snip>
info: Caching configuration at /var/lib/puppet/localconfig.yaml
err: Could not create root: Could not find a default provider for group
warning: file=/etc/yum.repos.d/: State group failed: Could not find a
default provider for group
2011 Mar 19
1
how to access the elements of a univariate results table with Anova (library car)
Dear R users, I use the excelent Anova function of the library car because
the easy way to get sphericity correction. Unless I use the scan function. I
have not been able to access the values of sum squares and degrees of
freedom for each effect in the univariate summary table.
Example of the car library for Anova function:
library(car)
phase <- factor(rep(c("pretest",
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
2012 Jul 21
2
car::Anova - Can it be used for ANCOVA with repeated-measures factors.
Dear list,
I would like to run an ANCOVA using car::Anova with repeated measures factors, but I can't figure out how to do it. My (between-subjects) covariate always interacts with my within-subject factors.
As far as I understand ANCOVA, covariates usually do not interact with the effects of interest but are simply additive (or am I wrong here?).
More specifically, I can add a covariate as
2009 Feb 18
2
[package-car:Anova] extracting residuals from Anova for Type II/III Repeated Measures ?
Hello dear R members.
I have been learning the Anova syntax in order to perform an SS type III
Anova with repeated measures designs (thank you Prof. John Fox!)
And another question came up: where/what are the (between/within) residuals
for my model?
############ Play code:
phase <- factor(rep(c("pretest", "posttest", "followup"), c(5, 5, 5)),
2007 Dec 31
3
Survival analysis with no events in one treatment group
I'm trying to fit a Cox proportional hazards model to some hospital
admission data. About 25% of the patients have had at least one
admission, and of these, 40% have had two admissions within the 12
month period of the study. Each patients has had one of 4
treatments, and one of the treatment groups has had no admissions for
the period. I used:
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
2009 Aug 03
1
survdiff for left-truncated data?
Hi
Does anyone know if there is a function like survdiff which can also handle
left-truncated and right-censored data? When I use it on left-truncated and
right-censored data I get an error message saying Right censored data only.
Many thanks
Rajen
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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
2010 Sep 02
2
date
Hello all,
I've 2 strings that representing the start and end values of a date and
time.
For example,
time1 <- c("21/04/2005","23/05/2005","11/04/2005")
time2 <- c("15/07/2009", "03/06/2008", "15/10/2005")
as.difftime(time1,time2)
Time differences in secs
[1] NA NA NA
attr(,"tzone")
[1] ""
How can i
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
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
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
2004 Apr 21
1
difference between coxph and cph
Hi. I am using Windows version of R 1.8.1. Being somewhat new to survival
analysis, I am trying to compare cph (Design) with coxph (survival) for use
with a survival data set.
I was wondering why cph and coxph provide me with different confidence
intervals
for the hazard ratios for one of the variables. I was wondering if I am
doing something wrong? Or if the two functions are calculating hazard
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
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