Displaying 20 results from an estimated 700 matches similar to: "Estimating correlation in multiple measures data"
2010 Mar 30
5
Problem comparing hazard ratios
Dear R-Helpers,
I am a novice in survival analysis. I have the following code:
for (i in 3:12) print(coxph(Surv(time, status)~a[,i], data=a))
I used it to fit the Cox Proportional Hazard models separately for every
available parameter (columns 3:12) in my data set - with intention to
compare the Hazard Ratios.
However, some of my variables are in range 0.1 to 1.6, others in range
5000 to
2010 May 26
3
Problem with plotting survival predictions from cph model
Dear R-helpers,
I am working with 'cph' models from 'rms' library. When I build simple
survival models, based on 'Surv(time, event)', everything is fine and I
can make nice plots using plot(Predict(f, time=3)).
However, recently I tried to be more specific and used 'Surv(start,
stop, event)' type model. Using this model 'plot(Predict(f))' works OK,
but
2009 Aug 05
1
Starting NONMEM (nmfe6) from R
Hello,
I have made an R script that prepares a NONMEM dataset and I would like
to start the NONMEM run right after the dataset is ready.
I am using windows XP, R 2.9.1 and NONMEM 6.
I have prepared a run.bat file that looks like this:
----------------------------------------
call K:\nmvi\NMdirectories.bat
call K:\nmvi\nmfe6 "path\control.txt" "path\output.txt"
2011 Aug 28
2
converting matrix in array
Hi everyone,
have a small problem trying to converting a dataset in matrix form to an
array.
Specifically: data include 3D measurement -x,y,z of 59 points in 36 objects.
They are stored as a matrix (x) of 2124 rows and 3 columns.
What I want to do is to extract each subject's dataset using an array (b).
Accordingly, I tried the following command:
b<-array(a,c(59,3,36)).
The problem is
2012 May 02
2
Problem with 'nls' fitting logistic model (5PL)
Dear R-Helpers,
I'm working with immunoassay data and 5PL logistic model. I wanted to
experiment with different forms of weighting and parameter selection,
which is not possible in instrument software, so I turned to R.
I am using R 2.14.2 under Win7 64bit, and the 'nls' library to fit the
model - I started with the same model and weighting type (1/y) as in the
instrument to see
2010 Aug 10
3
Plotting confidence bands around regression line
Dear R-helpers and graphics gurus,
I have two problems with plotting confidence bands:
1. First is relatively simple. I am using the Passing-Bablok procedure
to obtain "unbiased" regression coefficients. This procedure yields the
"a" & "b" coefficient values along with their confidence intervals. I
then plot the raw data with the regression line, but I would
2010 Oct 21
1
Big data (over 2GB) and lmer
Dear R-helpers
I have a data set of roughly 10 million records, 7 columns. It has only
about 500MB as a csv, so it fits in the memory. It's painfully slow to
do anything with it, but it's possible. I also have another dataset of
covariates that I would like to explore - with about 4GB of data...
I would like to merge the two datasets and use lmer to build a mixed
effects model. Is
2010 Apr 29
1
How to estimate the residual SD for each sample separately in mixed-effects model?
Dear R-helpers,
I am developing a Mixed-Effects model for a study of immunoassays using
'lme4' library. The study design is as follows: 10 samples were run
using 7 different immunoassays, 3 times each, in duplicates. Data
attached. I have developed the following model:
c.lme <- lmer(Result~SPL + (SPL|Assay/Run) -1, data=data)
This model has excellent predictions - the Rsquared of
2010 Jan 15
1
'nlme' library - lme function results
Dear R-helpers
I am running a simple mixed effects model using lme(). The call looks
like this:
fit <- lme(Analyte~Sample, data=Data, random=~1 | Run)
I am particularly interested in the estimated random effects. When I
print the 'fit' object, it looks something like example below:
(...)
Random effects:
Formula: ~1 | Run
(Intercept) Residual
StdDev: 3.483794 3.637523
2008 Jun 10
1
Problem with by(... , median)
Hello everyone,
I am new to R, I have been using SAS for a while. Not surprisingly, I
find R much better in graphics, which is publication ready right away.
Recently, I have been trying to calculate some basic statistics using R.
I have a dataset of multiple rows per subject. For example:
Subject Date Factor1 Factor2 Factor3
P1 0.5 1 1 3
P1 1 3 2 5
P1 2 3 5 NA
...
P2 0.5 1 6 4
P2 1 2 NA 7
P2
2008 Jul 21
5
Coefficients of Logistic Regression from bootstrap - how to get them?
Hello all,
I am trying to optimize my logistic regression model by using bootstrap.
I was previously using SAS for this kind of tasks, but I am now
switching to R.
My data frame consists of 5 columns and has 109 rows. Each row is a
single record composed of the following values: Subject_name, numeric1,
numeric2, numeric3 and outcome (yes or no). All three numerics are used
to predict
2008 Oct 17
2
Beginner's question: number formatting
Hello R-helpers,
I have a problem with formatting a single number to show leading zeros.
For example, I want "2" displayed as "002".
My numbers have 1 to 3 digits and I would like them all to display 3
digits for printing. I know I could use "paste" in a loop with several
"if"s, but I was wondering if there is a single function that can do this.
I have
2008 Jul 23
1
[Fwd: Re: Coefficients of Logistic Regression from bootstrap - how to get them?]
I think the argument supporting the use of bootstrap to determine
coefficients, as opposed to just running linear regression on the whole
dataset, is the comparison of Rsq and prediction errors between these
two approaches - page 1502. There's a substantial difference in favor of
the bootstrap approach.
--
Michal J. Figurski
Gustaf Rydevik wrote:
> The url for the mentioned paper is
2009 Jul 20
2
HELP: BRUGS/WinBUGS/RBUGS Response is a combination of random variables
Hi,
Is there anyone know if BUGS language allows the combination of variables as response
such as
Y[i] <- a*X1[i]+b*X2[i]
Y[i] ~ dnorm(c,d)
It seems doesn't work in my model. The problem is between two ######.
The error message is
> modelCheck("BayesBioMarker.BUGS")
model is syntactically correct
> modelData(paste("BUGS_data.txt",sep=""))
data
1997 Nov 19
7
Query
Hello All,
I am trying to compile Samba on POSIX under OpenVMS on a DEC 2000 AXP, however I am having difficulty defining the right FLAGSM and LIBSSM in the Makefile. So thus I'm having trouble getting the correct #includes, can anyone help?
Regards,
Gavin Butler
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2008 Jul 24
1
[Fwd: Re: Coefficients of Logistic Regression from bootstrap - how to get them?]
Thank you Frank and all for your advices.
Here I attach the raw data from the Pawinski's paper. I have obtained
permission from the corresponding Author to post it here for everyone.
The only condition of use is that the Authors retain ownership of the
data, and any publication resulting from these data must be managed by them.
The dataset is composed as follows: patient number / MMF dose in
2015 Feb 27
8
samba-tool time
Hai,
?
Can somebody try to run :
?
samba-tool time
and
samba-tool time servername.fqdn
?
when i run it, im getting :
?
ERROR(runtime): uncaught exception - Connection to SRVSVC pipe of server 'rotterdam.bazuin.nl' failed: NT_STATUS_NONE_MAPPED
? File "/usr/lib/python2.7/dist-packages/samba/netcmd/__init__.py", line 175, in _run
??? return self.run(*args, **kwargs)
? File
2008 Oct 06
1
Need to calculate within- and between- run CV
Dear R-helpers,
I have a dataset named "qu", organized as follows:
Sample Run Replicate Value
1 1 1 25
1 1 2 40
1 1 3 33
1 1 4 29
1 2 1 37
1 2 2 44
1 2 3 45
1 3 1 25
1 3 2 40
1 4 1 33
1 4 2 29
1 4 3 25
2 ...
Basically, a sample was run on an assay multiple times within a single
day. Each of these results is "Replicate". Then run was repeated several
times in
2015 Apr 27
2
[LLVMdev] seeking a mailing list for llvm ports
Hi - sorry to intrude, but can somebody point me to a suitable mailing
list where a tyro can get some advice on modifying an existing llvm
llvm assembler ... rather lightly?
I want to add an extra instruction to the assembler/machine code
supported by the OR1K llvm port.
Well, there are a few more things I need to do, but that will be
good enough to start with!
I was able to what I wanted
2001 May 03
3
Index vectors get overwriten ?!
Hello,
For some analysis of a mesh structure I need to prepare several vectors
of indexes of different length. This is done by the following code
sequence (including diagnostic output):
#--------------------------------------------------
MT_ind <- which(V1.frame[,2] %in% mm[,1])
print("M_ind")
str(M_ind)
Q1_ind <- which(V1.frame[,2] %in% mq1)
print("Q1_ind")