search for: baselining

Displaying 20 results from an estimated 1392 matches for "baselining".

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 Oct 05
3
SweaveInput + keep.source = TRUE trouble
Dear all, I have trouble with R-beta sweaving files that include definitions with \SweaveInput in combination with keep.source = TRUE Symptom: SInput is taken from too far down the input file (the shift is the number of lines of the included file). Is that known? Searching didn't turn up anything, yet I think there are more people than just me using keep.source. Example: $
2012 Apr 27
2
Deleting observations from baseline that don't appear in follow up
Hello all, I'm almost embarrassed to post this , it seems so easy. Suppose I have a baseline and follow up survey but some people are missing in the follow up: > baseline<-data.frame(id=c(3,5,7,9,12), data= runif(5)) > follow.up<-data.frame(id=c(3,7,9,12), data= runif(4)) > baseline id data 1 3 0.66771988 2 5 0.28794744 3 7 0.01892821 4 9 0.64863175 5 12 0.86485882
2006 Oct 22
1
Multilevel model ("lme") question
Dear list, I'm trying to fit a multilevel (mixed-effects) model using the lme function (package nlme) in R 2.4.0. As a mixed-effects newbie I'm neither sure about the modeling nor the correct R syntax. My data is structured as follows: For each subject, a quantity Y is measured at a number (>= 2) of time points. Moreover, at time point 0 ("baseline"), a quantity X is
2009 May 22
2
Error in FUN with tapply and by
A subset of my raw data looks like this: -------------- "Grip" "Technique" "Baseline.integrated" "Task" "Stroke..direction." "Engag" "Disen" "PenDG" "PenUG" "PenDS" "PenUS" "Duration" -------------
2012 Sep 01
5
R_closest date
Hi, I have encountered an issue about finding a date closest to another date So this is how the data frame looks like: PT_ID IDX_DT OBS_DATE DAYS_DIFF OBS_VALUE CATEGORY 13 4549 2002-08-21 2002-08-20 -1 183 2 14 4549 2002-08-21 2002-11-14 85 91 1 15 4549 2002-08-21 2003-02-18 181 89 1 16 4549 2002-08-21 2003-05-15
2005 Jun 10
1
Estimate of baseline hazard in survival
Dear All, I'm having just a little terminology problem, relating the language used in the Hosmer and Lemeshow text on Applied Survival Analysis to that of the help that comes with the survival package. I am trying to back out the values for the baseline hazard, h_o(t_i), for each event time or observation time. Now survfit(fit)$surv gives me the value of the survival function, S(t_i|X_i,B),
2011 Jan 18
2
Baseline terms for lrm
Dear R-help and Prof. Harrell: My question concerns the baseline state for continuous variable in lrm() within the RMS package. I have a model which can be reduced to: lrm(FT ~ rcs(V1, c(0, 1,5)) The model makes perfect sense if the baseline state is where V1>=5 but the model makes no sense if the baseline category is 0 (which I had expected). Can someone point me to a reference, or
2008 Sep 16
2
creating baseline variable from a longitudinal sequence
Dear R-help mailing list,   Kindly help me out with this problem:   I have a dataset that is in the format below, ID  time  Y  Age 1  0     195  23.1 1  2    204  23.3 1  4   202    23.5 2  0  170    22.0 2  3   234   22.2 3  0  208   24.4 3  2  194  24 .7 3  3   204  24.9   I wish to remove all the measurements at time point 0 and convert them to a baseline variable as follows;    ID  time  Y 
2004 Sep 17
1
Confused about specifying plot colors as RGB values
Based on reading 'rgb' documentation, I would have thought the following would have produced identical results. Can someone explain how to make this happen? I need to be able to specify an array of rgb values for the 'col' parameter. colnames.col <- c("black", "red", "blue", "green") colnames.rgb <- apply(as.matrix(colnames.col), 1,
2009 Dec 16
1
Baseline survival estimate
Dear R-help, I am trying to obtain the baseline survival estimate of a fitted Cox model (S_0 (t)). I know that previous posts have said use 'basehaz' but this gives the baseline hazard function and not the baseline survival estimate. Is there a way to obtain the baseline survival estimate or do I have to use the formula which does something like S(t) = exp[- the integral from 0 to t of
2001 Feb 22
3
[newbie] Cox Baseline Hazard
Hello everybody. First of all, I would like to present myself. I'm a french student in public health and I like statistics though I'm not that good in mathematics (but I try to catch up). I've discovered R recently while trying to find a statistical program in order to avoid rebooting my computer under windows when I need to do some statistical work. And here is my first question.
2011 Jan 18
0
analysis strategy - baseline and repeated measure
Hi, assume that I have a repeated measure dataset with 3 time points: baseline, day 5 and day 10. There are 4 treatment groups (vehicle, treatment 1, treatment 2 and treatment 3). 20 subjects per treatment group. A simple straight-forward way to analyze the data is to use mixed model: model 1: obj <- lmer(y ~ treatment * time +(time|subject)) where time is numeric with value 0,5 and 10.
2008 Jun 04
1
I am doing something wrong....
OK... I have relaid out my puppet dir as recommended in best practices: [jleggett@binford puppet]$ find . -print | grep -v .svn . ./plugins ./plugins/lines.pp ./files ./files/module ./files/module/SSH ./files/module/SSH/ssh_config ./files/module/SSH/sshd_config ./files/module/INFO ./files/module/INFO/motd ./files/module/INFO/issue ./files/module/NIS ./files/module/NIS/nsswitch.conf
2010 Mar 23
2
Sample size for proportion, not binomial
Hello, I am looking for a sample size function for samples sizes, to test proportions that are not binomial proportions. The proportions represent a ratio of (final measure) / (baseline measure) on the same experimental unit. Searches using RSeek and such bring multiple hits for binomial proportions, but that doesn't seem to fit my situation. Perhaps there's some standard terminology
2007 Feb 20
1
baseline fitters
I am pretty pleased with baselines I fit to chromatograms using the runquantile() function in caTools(v1.6) when its probs parameter is set to 0.2 and its k parameter to ~1/20th of n (e.g., k ~ 225 for n ~ 4500, where n is time series length). This ignores occasional low- side outliers, and, after baseline subtraction, I can re-adjust any negative values to zero. But runquantile's
2011 Oct 01
4
Is the output of survfit.coxph survival or baseline survival?
Dear all, I am confused with the output of survfit.coxph. Someone said that the survival given by summary(survfit.coxph) is the baseline survival S_0, but some said that is the survival S=S_0^exp{beta*x}. Which one is correct? By the way, if I use "newdata=" in the survfit, does that mean the survival is estimated by the value of covariates in the new data frame? Thank you very much!
2008 Feb 05
1
Extracting level-1 variance from lmer()
All, How does one extract the level-1 variance from a model fit via lmer()? In the code below the level-2 variance component may be obtained via subscripting, but what about the level-1 variance, viz., the 3.215072 term? (actually this term squared) Didn't see anything in the archives on this. Cheers, David > fm <- lmer( dv ~ time.num*drug + (1 | Patient.new), data=dat.new )
2011 Jan 03
3
Inverse Gaussian Distribution
Dear, I want to fit an inverse gaussion distribution to a data set. The predictor variables are gender, area and agecategory. For each of these variables I've defined a baseline e.g. #agecat: baseline is 3 data<-transform(data, agecat=C(factor(agecat,ordered=TRUE), contr.treatment(n=6,base=3))) The variable 'area' goes from A to F (6 areas: A,B,C,D,E,F) How can i
2016 Jun 30
0
New Aggressive Dead Code Elimination (updated)
I request additional review of diff: http://reviews.llvm.org/D18762 We noticed that a source of performance difference between llvm and gcc was in dead code elimination. This diff replaces ADCE with a new implementation which will remove control flow and, under option, also remove may-be-infinite loops which are dead. The patch current has "ADCE_new.h" and "ADCE_new.cpp" to