Displaying 20 results from an estimated 20000 matches similar to: "Mixed models with missing data"
2012 Aug 07
1
(no subject)
hi,?
I'm working on a research project where we're looking at the changing resonances in femur bones during hip replacement operations. basically, I've got a spreadsheet with one column listing frequencies in 5Hz bands and 3 columns showing the amplitude of that frequency when the bone is loose, medium to tight (referring to the tension of the reamer/chisel creating a cavity for the
2013 May 13
2
reduce three columns to one with the colnames
Ein eingebundener Text mit undefiniertem Zeichensatz wurde abgetrennt.
Name: nicht verf?gbar
URL: <https://stat.ethz.ch/pipermail/r-help/attachments/20130513/fe848ce7/attachment.pl>
2012 Jul 12
1
Results from mixed linear models
Dear list,
I'm quite confused when interpreting results from a mixed linear model.
For example, working on Iris data frame, I want to know the effect of
species on slope of the model "Petal.Length~Sepal.Length"
I write this :
data(iris)
reg01 <- lm(Petal.Length~Sepal.Length + Sepal.Length:Species, data=iris)
summary(reg01)
It gives me a summary table with lm for the first
2013 Jun 18
2
find closest value in a vector based on another vector values
Dear All,
would you please provide your thoughts on the following:
let us say I have:
a <-c(1,5,8,15,32,69)
b <-c(8.5,33)
and I would like to extract from "a" the two values that are closest to the values in "b", where the length of this vectors may change but b will allways be shorter than "a". So at the end based on this example I should have the result
2012 Sep 14
1
linear mixed-effects models with two random variables?
Dear R users,
Does anyone knows how to run a glmm with one fixed factor and 2 random
numeric variables (indices)? Is there any way to force in the model a
separate interaction of those random variables with the fixed one?
I hope you can help me.
#eg.
Reserve <- rep(c("In","Out"), 100)
fReserve <- factor(Reserve)
DivBoulders <- rep
2012 Jul 24
1
Convenience function to get unevaluated ... function arguments
Folks:
Herein is a suggestion for a little R convenience function mainly to
obtain unevaluated ... function arguments. It arose from a query on
R-help on how to get these arguments. The standard (I think) idiom to
do this is via
match.call(expand.dots=FALSE)$...
However, Bill Dunlap pointed out that this repeats the argument
matching of the function call and suggested a couple of alternatives
2012 Dec 17
2
Mixed Anova
I am new to R and have been doing my utmost to learn it in order to teach my
students how to use it as an alternative to programs you have to purchase
and I am very grateful for the program and what it can doŠ.but I am having a
slight problem as I also am not very much into programming though willing
to learn.
I have been trying to apply a mixed model ANOVA to some data I have. In
short one
2012 Sep 12
3
Need help
Hello,
I am brand new in this site as well as in R. Please accept my early apology if it's not the right place to ask such a question.
I have the following equation:
b=[2(1-a)(1+2a)^0.5]/(1+3a)
How can I solve the above equation for 'a' using R?
Thanks in advance.
KD
[[alternative HTML version deleted]]
2012 Jul 23
3
How to do the same thing for all levels of a column?
Dear all,
I am a R beginner, and I am looking for a way to do the same thing for all
levels of a column in a table.
Basically, I have a bunch of protein sequences composed of different amino
acid residues, and each residue is represented by an uppercase letter. I
want to calculate the ratio of different amino acid residues at each
position of the proteins. Here is an example table:
Proteins
2012 Mar 21
1
Doubts about mixed effect models
Hi everyone!
I have some doubts about mixed effect models and I hope someone could help
me. I´m trying to analyze a dataset coming from samples of dung beetles in
the same forest fragments along 3 consecutive years (1994, 1995 and 1996)
and 14 years after (2010). I sampled dung beetles in 18 different fragments
with different sizes and different degrees of isolation. My aim is to
determine
2012 Jul 26
1
Testing significance of interaction between group and longitudinal change for part of the age range in a mixed linear model
Hi all,
I've fit a mixed linear model to some longitudinal data. I'm interested in the differences in patterns of decrease in the dependent variable according to group status, and my hypothesis particularly predicts a difference between the groups in trajectory of change at between specific ages. The data shows a significant interaction between group and the linear and quadratic effects
2012 Aug 17
1
Linear mixed model using R
Dear all,
I am trying to use R to fit mixed models.
Take the following example, where ind is a random effect and
sample is fixed. I wanted to fit
Model 1: values = ind + sample
Model 2: values =ind * sample
Model 3: values=ind(sample) + sample
Tried to use the below for mod1, but it did not work. Can anyone give
some help on this. Thanks so much.
mod1 <- lme(values ~ sample +
2013 Mar 09
2
grouping followed by finding frequent patterns in R
I have a data in the following form :
CIN TRN_TYP
9079954 1
9079954 2
9079954 3
9079954 4
9079954 5
9079954 4
9079954 5
9079954 6
9079954 7
9079954 8
9079954 9
9079954 9
. .
. .
. .
there are 100 types of CIN (9079954,12441087,15246633,...) and respective
TRN_TYP
first of all, I want this data to be
2012 Feb 23
5
cor() on sets of vectors
suppose I have two sets of vectors: x1,x2,...,xN and y1,y2,...,yN.
I want N correlations: cor(x1,y1), cor(x2,y2), ..., cor(xN,yN).
my sets of vectors are arranged as data frames x & y (vector=column):
x <- data.frame(a=rnorm(10),b=rnorm(10),c=rnorm(10))
y <- data.frame(d=rnorm(10),e=rnorm(10),f=rnorm(10))
cor(x,y) returns a _matrix_ of all pairwise correlations:
cor(x,y)
2012 Oct 11
3
Sorting a data frame by specifying a vector
Hello all,
I cannot seem to figure out this seemingly simple procedure.
I want to sort a data frame by a specified character vector.
So for :
df.. <- data.frame(Season=rep(c("Summer","Fall","Winter","Spring"),4),Obs=
runif(length(rep(c("Summer","Fall","Winter","Spring"),4))))
I want to sort the data frame
2012 Sep 27
1
Problem with grid.rect
I have a stupid problem that is currently driving me crazy...
Let us suppose that I want to draw a big red square in the middle of my
current device (say X11)
I tried the following code :
pushViewport(viewport(xscale=c(0,1), yscale=c(0,1)), just=c("center", "center"))
vp1 <- viewport(x=unit(0.5, "native"), y=unit(0.5, "native"),
width=unit(0.4,
2012 Sep 25
3
(core) designation on Task View
Hello,
Does the (core) designation in the CRAN Task View indicate packages
that provide basic/recommended functionality in that domain?
I don't see it documented anywhere on the site.
Thanks for your help.
2012 Sep 01
2
(Newbie) help cannot find chrome
Following the beginning tutorial, I typed help.start() and was given a
choice of browsers. I picked chrome but got back that chrome is not found.
I cannot seem to change or get rid of it now.
I looked at /etc/R/Renviron but don't see anywhere to set browser
(R_BROWSER = ${R_BROWSER ...etc) - nothing about chrome.
I tried starting as "R_BROWSER= R" - same thing.
How do I change the
2012 Jan 11
2
2D filter in R?
Hi all,
I am looking for a command for doing 2D filtering (rectangular or
Gaussian) in R...
I have looked at ksmooth, filter and convolve but they seem to be 1D...
Any thoughts?
Thanks a lot!
[[alternative HTML version deleted]]
2011 Oct 11
2
replicate data.frame n times
Hi,
is there a way to replicate a data.frame like you can replicate the entries of a vector (with the repeat-function)?
I want to do this:
x <- data.frame(x, x)
(where x is a data.frame).
but n times.
And it should be as cpu / memory efficient as possible, since n is pretty big in my case.
thanks for any suggestions!