Displaying 20 results from an estimated 200 matches similar to: "analysing mixed effects/poisson/correlated data"
2008 Apr 28
2
F values from a Repeated Measures aov
Hi Folks,
I have repeated measures for data on association time (under 2
acoustic condtions) in male and female frogs as they grow to adulthood
(6 timepoints). Thus, two within-subject variables (Acoustic
Condition: 2 levels, Timepoint: 6 levels) and one between-subject
variable (Sex:male or female).
I am pretty sure my distributions depart from normality but I would
first like to simply run a
2009 Oct 25
3
Importing data from text file with mixed format
Hi,
I'm having difficulty importing my textfile that looks something like this:
#begin text file
Timepoint 1
ObjectNumber Volume SurfaceArea
1 5.3 9.7
2 4.9 8.3
3 5.0 9.1
4 3.5 7.8
Timepoint 2
ObjectNumber Volume SurfaceArea
1 5.1
2007 Jul 09
2
ANOVA: Does a Between-Subjects Factor belong in the Error Term?
I am executing a Repeated Measures Analysis of Variance with 1 DV (LOCOMOTOR
RESPONSE), 2 Within-Subjects Factors (AGE, ACOUSTIC CONDITION), and 1
Between-Subjects Factor (SEX).
Does anyone know whether the between-subjects factor (SEX) belongs in the
Error Term of the aov or not? And if it does belong, where in the Error Term
does it go? The 3 possible scenarios are listed below:
e.g.,
1.
2010 Sep 16
1
ANOVA - more sophisticated contrasts
dear list,
i am using a multifactorial design with two treatments (factor A: drugs,
three levels; factor B: theraphy, two levels) and a time factor (three
levels, different timepoint). hypothetically, i measured the same subjects
for all treatements and timepoints, so its a repeated measurement design.
now i ran an anova in R and also some Tukey post-hoc tests using glht. but
what i am actually
2010 Sep 19
1
boyplots nearly identical but still highly significant effect?
dear list,
i am running a within-design ANOVA with 4 factors (4,4,2 and 2 levels each).
the last one is a time factor comprising two different treatment timepoints.
i fit a mixed-effects model using lme and apply the anova function to the
outcome. according to this analysis, there are highly significant main
effect on the first and the time factor. i then checked the boxplots for the
two 4-level
2009 Sep 02
2
Average over data sets
Hello,
I have a number of files output1.dat, output2.dat, ... , output20.dat,
each of which monitors several variables over a fixed number of
timepoints. From this I want to create a data frame which contains the
mean value between all files, for each timepoint and each variable.
The code below works, but it seems like I should be able to do the
second part without a for loop. I played
2013 Apr 01
1
Help Please, ggplot2
library(ggplot2)
a<- read.table("data", header=T)
b = na.omit(a)
ggplot(data=b) + geom_line(aes(x=timepoint, y=value,group=sample, colour= factor(sample))) +? geom_point(aes(x=timepoint, y=value, group=s
ample)) + facet_wrap(~bio, scales = "free",ncol = 5) +theme_bw() + opts(legend.direction = "horizontal",??? legend.position = "top",????
2012 Feb 20
1
Reporting Kaplan-Meier / Cox-Proportional Hazard Standard Error, km.coxph.plot, survfit.object
What is the best way to report the standard error when publishing
Kaplan-Meier plots? In my field (Vascular Surgery), practitioners
loosely refer to the "10% error" cutoff as the point at which to stop
drawing the KM curve. I am interpreting this as the *standard error
of the cumulative hazard*, although I'm having a difficult time
finding some guidelines about this (perhaps I am
2006 Oct 27
1
Censored Brier Score and Royston/Sauerbrei's D
System: R 2.3.1 on a Windows XP computer.
I am validating several cancer prognostic models that have been
published with a large independent dataset. Some of the models report a
probability of survival at a specified timepoint, usually at 5 and 10
years. Others report only the linear predictor of the Cox model.
I have used Harrell's c index for censored data (rcorr.cens) as a
measure of
2007 Nov 20
1
Vectorization/Speed Problem
Hi,
I cannot find a 'vectorized' solution to this 'for loop' kind of problem.
Do you see a vectorized, fast-running solution?
Objective:
Take the value of X at each timepoint and calculate the corresponding value
of Y. Leading 0's and all 1's for X are assigned to Y; otherwise Y is
incremented by the number of 0's adjacent to the last 1. The frequency and
2010 Jun 10
1
do faster ANOVAS
Dear all R users,
I want to realize 800 000 ANOVAS and to store Sum of Squares of the effects. Here is an extract of my table data
Product attribute subject rep t1 t2 t3 … t101
P1 A1 S1 R1 1 0 0 … 1
I want to realize 1 ANOVA per timepoint and per attribute, there are 101 timepoints and 8 attributes so I want to realize 808 ANOVAS. This will be an ANOVA with two factors :
Here is one example:
2004 Apr 08
0
lme, mixed models, and nuisance parameters
I have the following dataset:
96 plots
12 varieties
2 time points
The experiment is arranged as follows:
A single plot has two varieties tested on it.
With respect to time points, plots come in 3 kinds:
(1) varietyA, timepoint#1 vs. variety B, timepoint#1
(2) varietyA timepoint #2 vs. varietyB timepoint #2
(3) varietyA timepoint #1 vs. variety A timepoint#2
- there are 36 of each kind
2007 Apr 18
1
undefined symbol: Rf_rownamesgets
I get the error
undefined symbol: Rf_rownamesgets
when I try to load my package, which include C++ code that calls that
function. This is particularly strange since the code also calls
Rf_classgets, and it loaded OK with just that.
Can anyone tell me what's going on?
For the record, I worked around this with the general purpose
attribute setting commands and R_RowNamesSymbol. I
2004 Mar 18
1
two lme questions
1) I have the following data situation:
96 plots
12 varieties
2 time points
2 technical treatments
the experiment is arranged as follows:
a single plot has two varieties tested on it. if variety A on plot #1 has
treatment T1 applied to it, then variety B on plot #1 has treatment T2
applied to it. across the whole experiment variety A is exposed to
treatment T1 the same number of times as
2012 Jun 20
2
reshape
Hello, helpeRs,
I am attempting to reshape (either base R or package reshape) multiple .csv
spreadsheets from a very unfortunate wide format to long format. ?Each spreadsheet
looks something like this, after being read in to R:
toy <- data.frame(year = rep(2007:2008,each = 20), month = rep(1:5,each = 4, length = 40),
day = rep(1:2,each = 2,length = 40), hhmm = rep(1100:1101,length = 40),
2011 Jun 24
1
UnoC function in survAUC for censoring-adjusted C-index
Hello,
I am having some trouble with the 'censoring-adjusted C-index' by Uno et al, in the package survAUC. The relevant function is UnoC.
The question has to do with what happens when I specify a time point t for the upper limit of the time range under consideration (we want to avoid using the right-end tail of the KM curve).
Copying from the example in the help file:
TR <-
2013 Jan 24
4
sorting/grouping/classification problem?
Hi,
I'm a database admin for a database which manage chromatographic results of products during stability studies.
I use R for the reporting of the results in MS Word through R2wd.
But now I think I need your help:
suppose we have the following data frame:
ID rrt Mnd Result
1 0.45 0 0.10
1 0.48 0 0.30
1 1.24 0 0.50
2 0.45 3 0.20
2 0.48 3 0.60
2 1.22 3 0.40
3
2004 May 05
1
Granule Pos of start of page...
OK... i've come across a problem trying to get the granule pos of the start
of the page... it's not so crucial with single stream ogg files... but now
that i have theora+vorbis in a file, i'm finding that when i seek to a
position, i have no way to determine the relative offsets of the different
streams at the new seek point and hence the av is out of sync.
So given a page, is it
2008 Sep 02
2
Help with nonlinear regressional
Dear All,
I am doing experiments in live plant tissue using a laser confocal
microscope. The method is called "fluorescence recovery after
photo-bleaching" (FRAP) and here follows a short summary:
1. Record/ measure fluorescence intensity in a defined, round region of
interest (ROI, in this case a small spot) to determine the initial intensity
value before the bleaching. This
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 )