Displaying 20 results from an estimated 800 matches similar to: "creating variable that codes for the match/mismatch between two other variables"
2009 Apr 01
1
Help with mixed-effects model with temporal pseudoreplication!
Sorry if this is the wrong ml for this question, I am new to R. I am
trying to use R to analyze the data from my thesis experiment and I am
having troubles accounting for the pseudoreplication properly from
having each participant repeat each treatment combination (combination
of fixed factors) 5 times. The design of the experiment is as
follows...
Responses:
CompletionTIme
VisitedTargets
2011 Jan 05
1
Comparing fitting models
Dear all,
I have 3 models (from simple to complex) and I want to compare them in order to
see if they fit equally well or not.
From the R prompt I am not able to see where I can get this information.
Let´s do an example:
fit1<- lm(response ~ stimulus + condition + stimulus:condition, data=scrd)
#EQUIVALE A lm(response ~ stimulus*condition, data=scrd)
fit2<- lm(response ~ stimulus +
2011 Jan 05
2
Problem with 2-ways ANOVA interactions
Dear All,
I have a problem in understanding how the interactions of 2 ways ANOVA work,
because I get conflicting results
from a t-test and an anova. For most of you my problem is very simple I am sure.
I need an help with an example, looking at one table I am analyzing. The table
is in attachment
and can be imported in R by means of this command:
scrd<-
2005 Dec 01
1
LME & data with complicated random & correlational structures
Dear List,
This is my first post, and I'm a relatively new R user trying to work out a
mixed effects model using lme() with random effects, and a correlation
structure, and have looked over the archives, & R help on lme, corClasses, &
etc extensively for clues. My programming experience is minimal (1 semester
of C). My mentor, who has much more programming experience, but a comparable
2011 Jan 07
2
anova vs aov commands for anova with repeated measures
Dear all,
I need to understand a thing in the beheaviour of the two functions aov and
anova in the following case
involving an analysis of ANOVA with repeated measures:
If I use the folowing command I don´t get any problem:
>aov1 = aov(response ~ stimulus*condition + Error(subject/(stimulus*condition)),
>data=scrd)
> summary(aov1)
Instead if I try to fit the same model for the
2011 Jan 09
2
Post hoc analysis for ANOVA with repeated measures
Dear all,
how can I perform a post hoc analysis for ANOVA with repeated measures (in
presence of a balanced design)?
I am not able to find a good example over internet in R...is there among you
someone so kind to give
me an hint with a R example please?
For example, the aov result of my analysis says that there is a statistical
difference between stimuli (there are 7 different stimuli).
...I
2006 May 11
2
greco-latin square
Hi,
I am analyzing a repeated-measures Greco-Latin Square with the aov command.
I am using aov to calculate the MSs and then picking by hand the appropriate
neumerator and denominator terms for the F tests.
The data are the following:
responseFinger
mapping.code Subject.n index middle ring
little
----------------------------------------------------------------------------
1 1
2007 Aug 02
1
ggplot2 qplot and add
Hi there,
I have some simple frequencies I want to plot into one graph. I had it
working, and now I can't figure out whats going wrong. All the data is
stored in a dataframe, and i finally managed to order the factor correctly!
Each column is a variable and contains integers for the same set of values
in the column that contains the headers for each row (graphLabels).
So, I get the data
2010 Jun 13
1
Pairwise cross correlation from data set
Dear list,
Following up on an earlier post, I would like to reorder a dataset and
compute pairwise correlations. But I'm having some real problems
getting this done.
My data looks something like:
Participant Stimulus Measurement
p1 s`1 5
p1 s`2 6.1
p1 s`3 7
p2 s`1 4.8
p2
2011 Jan 08
1
Anova with repeated measures for unbalanced design
Dear all,
I need an help because I am really not able to find over internet a good example
in R to analyze an unbalanced table with Anova with repeated measures.
For unbalanced table I mean that the questions are not answered all by the same
number of subjects.
For a balanced case I would use the command
aov1 = aov(response ~ stimulus*condition + Error(subject/(stimulus*condition)),
data=scrd)
2011 Oct 07
1
ANOVA/ANCOVA Repeated Measure Mixed Model
Hello,
I am trying to test some results I have for significance. It has been
recommended that I use R and I am completely new to this.
Set-up:
Groups: two groups of 8 subjects (16 total)
Two conditions: alert and passive
Measurements: responses for three different stimuli (A, B, and C)
measured in each condition
Experiment: Testing the order of conditions
Group one: Alert A, B
2006 Oct 06
2
Fitting a cumulative gaussian
Dear R-Experts,
I was wondering how to fit a cumulative gaussian to a set of empirical
data using R. On the R website as well as in the mail archives, I found
a lot of help on how to fit a normal density function to empirical data,
but unfortunately no advice on how to obtain reasonable estimates of m
and sd for a gaussian ogive function.
Specifically, I have data from a psychometric function
2003 Jun 11
1
COX PH models for event histories?
This is a question about the use of the Cox proportional hazards model to analyze event histories.
I am looking at the responses of sympathetic nervous system activity to a stimulus. The activity I observe is a burst that can only occur once per heart beat cycle (e.g., a binary count). Typically bursts occur in 60-80% of the heart cycles * sensory stimuli can modify these burst probabilities.
2011 Jan 27
2
Extrapolating values from a glm fit
Dear R-help,
I have fitted a glm logistic function to dichotomous forced choices
responses varying according to time interval between two stimulus. x values
are time separation in miliseconds, and the y values are proportion
responses for one of the stimulus. Now I am trying to extrapolate x values
for the y value (proportion) at .25, .5, and .75. I have tried several
predict parameters, and they
2008 Apr 15
1
Predicting ordinal outcomes using lrm{Design}
Dear List,
I have two questions about how to do predictions using lrm, specifically
how to predict the ordinal response for each observation *individually*.
I'm very new to cumulative odds models, so my apologies if my questions are
too basic.
I have a dataset with 4000 observations. Each observation consists of
an ordinal outcome y (i.e., rating of a stimulus with four possible
2008 Dec 12
1
Support vector model?
Dear All,
Apologies for sending this email to both list, but at this point I'm not
sure which one could help me the most.
I have 4 sets of data, 1 test and 3 different sets of controls.
The measurements are binary, with a matrix of 0 and 1
I'm measuring across time (rows, ~815) the behaviour of organelles in
the cell by microscopy in response to different stimuli (several
measurements
2006 Mar 18
1
Time-Series, multiple measurements, ANOVA model over time points, analysis advice
Hi,
I have some general questions about statistical analysis for a research
dataset and a request for advice on using R and associated packages for a
valid analysis of this data. I can only pose the problem as how to run
multiple ANOVA tests on time series data, with reasonable controls of the
family-wise error rate. If we run analysis at many small sections of a long
time-series, the Type-I
2012 Feb 10
3
Creating XML document extremely slow
Hi list,
I'm using the package XML to create a simple XML document.
Unfortunately constructing the XML tree is extremely slow. My code
(see below) adds only about 100 nodes per second on an Intel i5
machine. There's clearly something wrong but I don't see what.
Here's a sample of the XML document:
<?xml version="1.0" encoding="utf-8"?>
2003 Oct 09
1
nlme & lme for complex mixed ANOVAs
Dear List,
I downloaded R for the first time yesterday, in the hopes that I might
deal more effectively with a complex repeated measures experimental
design involving inbred strains of laboratory mice. The design below,
somewhat simplified, cannot be computed with standard ANOVA, because
something called the X'X matrix is too large. The design has the
following factors:
Between-subject
2011 Mar 21
1
Audio Performance on solo instruments
Hello everyone, I was curious if anyone has performed any listening tests or
done work with solo instrument performances with the CELT codec?
I experience quite a bit of noise coming up with a heavily tonal stimulus,
the worst offender being a trumpet. I understand some of this behavior is to
be expected, this is a perceptual codec afterall, but was curious if anyone
was able to find an elegant