Displaying 20 results from an estimated 600 matches similar to: "Clogit or LRM?"
2009 Aug 05
1
Question with apply function
In my continuing quest to generate some summary data, I've come across
some useful suggestions in pasts posts.
The apply operation returns an error, and I can't figure out why.
Can someone help me fix this?
testlogdata <- cbind(testlogdata, range_group=cut(testlogdata$lrm_score,
breaks=c(.9, .8, .7, .6, .5, .4, .3, .2, .1)))
apply(testlogdata, 2, function(x){tapply(x,
2003 May 21
2
Graphics device history recording problem (Previous and Next utilities)
I use 1.7.0 version under Windows XP.
Problem:
When graphics device history recording function turned
on, suppose I source a file containing lines:
plot(graph1)
plot(graph2)
I see the graph2 in the graphic device, assuming
graph2 is the last plot in the file. Now using
"Previous" under history menu, I get graph1 as
expected. But after that, using "Next" does not show
graph2.
2008 Jan 30
2
Concatenate xyplots
Dear R-community,
I created 5 different xyplots and graphed all of them with the print command on one page (e.g.
print(graph1, split=c(1,1,1,5), more = T)
... print(graph5, split=c(1,5,1,5), more =T)
Using the above commands separates each graph by a white space. However, since the graphs do share the same x-axis, I was wondering if there is a way to concatenate graph1 through 5 so
2010 Nov 19
1
How to print "graph1.png" "graph2.png" "graph3.png" ... ?
Dear All,
I want to print out "graph1.png" "graph2.png" "graph3.png" ... How
can I print it out?
Thank you,
2013 Jun 19
2
knitr without R studio
Hello folks,
I`m using knitr on R studio, which make it easy to use, but a coworker of
mine would like to run it on "simple" R. So I was wondering if you know what
is the equivalent of the button "knit HTML" in RStudio in R. I tried
knit2HTML(
<html>
<head>
<title></title>
</head>
<body style="background-color:white">
2011 Jul 12
4
qplot and for loops
I have 4 columns and 56 rows of made up data that I want to plot as a series
of bar graphs. The idea is to create one bar graph for each of the 4 columns
using a for loop. I tried the following command in RStudio and when I type x
in the console I get just the 4th graph instead of all four graphs. I did
not define what x is before hand. I was not sure what it would be. Any
suggestions on how you
2004 Apr 03
2
a fix for rotated PDF graphs
Hi,
I have found references for the following problem in the list
archives, but no nice solution. So I decided to post one I came up
with.
The problem is that graphs output as eps files, for example using
ps.options(onefile=FALSE, paper="special", width=8, height=8,
horizontal=FALSE, pointsize=12)
get rotated when I convert them to pdf using epstopdf. Both ghostview
and
2016 Apr 26
0
survival::clogit, how to extract residuals for GOF assessment
Hi Folks,
Hopefully this question has enough R and not too much stats to be
appropriate for this list. Based on,* Hosmer et al. 2013. Logistic
regression for matched case-control studies. Applied Logistic
Regression *(eqtn.
7.8)*, *I am assessing GOF of conditional (or matched) logistic regression
models with the *standardized Pearson residuals*. The authors define
?large? as delta chi-squared
2006 Jul 29
0
Help with clogit in survival - conditional logistic regression
Dear All:
I have been struggling to run the conditional logistic regression on a
dataset. I am using clogit function in survival package. Here is how the
data is generated. I tried to shorted the data by using the second count
variable but still the clogit did not run. Why I am not able to run clogit
on my dataset. I appreciate any input.
Regards,
Ashraf
age <- c(rep(0,8),rep(1,8))
scc <-
2009 Sep 11
2
Graph visualization
Hello,
I am working with graph and adjacency matrix, the package 'graph' seems to be appropriate for this.
An example in the package
> mat <- rbind(c(0, 0, 1, 1),
+ c(0, 0, 1, 1),
+ c(1, 1, 0, 1),
+ c(1, 1, 1, 0))
> rownames(mat) <- colnames(mat) <- letters[1:4]
> graph1 <- new("graphAM", adjMat=mat)
> graph1
A
2011 Nov 07
2
help with formula for clogit
I would like to know if clogit function can be used as below
clogit(group~., data=dataframe)
When I try to use in above format it takes a long time, I would appreciate
some pointers to get multiple combinations tested.
set.seed(100)
d=data.frame(x=rnorm(20)+5,
x1=rnorm(20)+5,
x2=rnorm(20)+5,
x3=rnorm(20)+5,
x4=rnorm(20)+5,
x5=rnorm(20)+5,
x6=rnorm(20)+5,
x7=rnorm(20)+5,
x8=rnorm(20)+5,
2008 Nov 07
0
clogit and small sample sizes: what to do?
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
Conditional logistic regression and small sample sizes: what to do?
Dear R-Gurus,
[I run R 2.8.0 on WinXP. I have no formal training in statistics.]
Please feel free to skip the 'Blah blah part' for questions below.
- ---Blah blah part--------
Why I use clogit (package 'survival')?: I am looking for risk factors
for cases during a
2004 Jun 06
0
strata() in clogit()
How can I get the log odds associated with the levels in strata()
within a clogit() model? I'm running R-1.9.0 on a Linux platform.
I am using clogit() to run a Rasch model in Item Response Theory in
psychometrics. Symbolically, the model is:
logit(p_{j,k}) = \log({\Pr(p_{j,k}) \over \Pr(1-p_{j,k})}) =
\theta_j - \alpha_k,
That is, the log odds of answering an test item correctly is
2006 Mar 23
2
clogit question
Hi,
I am playing with
clogit(case~spontaneous+induced+strata(stratum),data=infert)
from clogit help file.
This line works.
1. But, why strata(stratum) doesn't have a coefficient like spontaneous
and induced?
2. When I remove strata(stratum) from the command, this function seems
to keep running forever. Why?
3. I think the equation for clogit looks like
P=1/(1+
2011 Dec 21
1
Processing time on clogit
Hi All,
I'm trying to run a conditional logistic regression in R (2.14.0) using
clogit from the survival package. The dataset I have is relatively small
(300 observations) with 25 matched strata- there are roughly 2 controls for
each case, and some strata have multiple case/control groups. When I try to
fit a very simple model with a binary outcome and a single continuous
exposure R seems to
2006 Feb 16
1
prediction function for clogit model
Dear R-Help,
I wonder if there is a prediction function for a clogit model which can be
used in the same way as the predict function for the multinom model.
In prediction('multinommodel',testset ...) it is possible to predict the
class or the class probabilities for a testset. There is a predict function
for the coxph model but I cannot find an way to use this to predict the
classes
2009 Jul 08
1
clogit comparison between Stata and R
Hello all
I'm moving back and forth between stata and R at the moment - of course,
using R whenever possible :-)
I'm running conditional logits on some panel data and I get slightly
different results and different N in the two programs.
In R I run
clogit(trans.dem ~ I(avg.gle_rgdp.500/gle_rgdp) + log(gle_rgdp) +
timesince.dem + I(timesince.dem^2) + timesince.dict + I(timesince.dict^2) +
2005 Dec 08
0
Assessing fit for non-nested models using clogit in survival package
I am analyzing a 1-to-2 matched case-control study using clogit in the
survival package. I am interested in comparing and assessing fit of
non-nested models. I don't want to program all the diagnostics
described in Hosmer/Lemeshow (2000). Can someone proficient with clogit
and assessing fit for non-nested models point me in the right
direction.
Many thanks!
Tomas
Tomas Aragon, MD, DrPH
Tel:
2008 Apr 25
0
function clogit
Hello,
I am using the clogit (conditional logistic regression) on a simple data set which is not related to survivorship, which I understand to be fine.
I have trouble understanding the output. I would like to find parameter estimates of the logistic models I am constructing with R, and am unclear as to what the coefficients represent that are provided.
The below is a copy of my output.
2010 Apr 20
1
Results from clogit out of range?
Hi,
I'm calculating a conditional logit on some data stratified by group.
My understanding was that a conditional logit by definition returns a
value between 0 and 1 a a probability. Can anyone suggest why I'm
seeing results outside of the {0,1} range??
The call in R is:
m <- clogit(score ~ val_1 + val_2 + strata(group), data=data)
Then
prediction <- predict(m,newdata)
A