Displaying 20 results from an estimated 2000 matches similar to: "Continous variables with implausible transformation?"
2011 Jun 20
2
Error of Cross Validation
Dear R users:
Recently, I tried to write a program to calculate cross-validated predicted
value.
My sources are as follows. However, the R reported an error.
Could you please check the sources? Thanks.
set.seed(100)
x<-rnorm(100)
y<-sample(rep(0:1,50),replace=T)
dat<-data.frame(x,y)
library(rms)
fito<-lrm(y~x)
preo<-predict(fito)
pre<-matrix(NA,nrow=100,ncol=200)
for (i in
2010 Jan 21
3
cross validation function translated from stata
Hi, everyone:
I ask for help about translating a stata program into R.
The program perform cross validation as it stated.
#1. Randomly divide the data set into 10 sets of equal size, ensuring equal
numbers of events in each set
#2. Fit the model leaving out the 1st set
#3. Apply the fitted model in (2) to the 1st set to obtain the predicted
probability of a prostate cancer diagnosis.
#4. Repeat
2008 Jul 19
1
Discretize continous variables....
Hi R helpers,
I'm preparing dataset to fir logistic regression model with lrm(). I
have various cointinous and discrete variables and I would like to:
1. Optimaly discretize continous variables (Optimaly means, maximizing
information value - IV for example)
2. Regroup discrete variables to achieve perhaps smaller number of
level and better information value...
Please suggest if there is
2009 Sep 12
2
could not find function "Varcov" after upgrade of R?
After upgrading R to 2.9.2, I can't use the anova() fuction.
It says "could not find function "Varcov" ".
What's wrong with my computer? Help needed, thanks!
Yao Zhu
Department of Urology
Fudan University Shanghai Cancer Center
No. 270 Dongan Road, Shanghai, China
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2011 Apr 22
2
How to answer the question about transitive correlation?
Hi, everyone. I know it may be a basic statistical question. But I can't
find a good answer.
I have a question raised by one of the reviewers.
Factor A expression was strongly correlated with B expression (chi-square)
in this series. Prior reports by the same authors showed that B expression
strongly correlated with survival (Log-rank). Please provide an explanation
why then were the results
2010 Aug 17
2
HMisc/rms package questions
1) How does one capture the plots from the plsmo procedure? Simply
inserting a routing call to a graphical device (such as jpeg, png, etc)
and then running the plsmo procedure (and then dev.off()) does not route
the output to the file system. 1b) Related to above, has anyone thought
of revising the plsmo procedure to use ggplot? I'd like to capture
several such graphs into a faceted
2010 Oct 13
1
bootstrap in pROC package
Dear useRs:
I use pROC package to compute the bootstrap C.I. of AUC.
The command was as follows:
roc1<-roc(all$D,all$pre,ci=TRUE,boot.n=200)
However, the result was:
Area under the curve: 0.5903
95% CI: 0.479-0.7016 (DeLong)
Why the C.I. was computed by the Delong Method?
Yao Zhu
Department of Urology
Fudan University Shanghai Cancer Center
Shanghai, China
[[alternative HTML version
2015 Nov 10
2
Differences from upstream RHEL
--On Tuesday, November 10, 2015 12:53:20 PM -0800 Gordon Messmer
<gordon.messmer at gmail.com> wrote:
> That depends on what you mean by "support."
>
> It's almost certainly possible to run the binaries on CentOS, but if you
> need any technical support from the vendor of that application, they
> might not provide it. Your first step should be to talk to them
2013 Jun 24
2
Nomogram (rms) for model with shrunk coefficients
Dear R-users,
I have used the nomogram function from the rms package for a logistic
regresison model made with lrm(). Everything works perfectly (r version
2.15.1 on a mac). My question is this: if my final model is not the one
created by lrm, but I internally validated the model and 'shrunk' the
regression coefficients and computed a new intercept, how can I build a
nomogram using that
2003 Apr 08
1
Solving A System of Equations
I'm trying to solve a system of 3 equations as part of a sub-routine in R, ie first eqn a/x-b*sqrtx+c=log(1/dx+1/e(sqrtx); snd eqn (f*y)/z-g/y-h=-log(2/x+(z/y)/(i*x) and third eqn is of the form zz=x/(j-k(z/y)
where a..k inclusive are constants, x,y,z and zz are inputs.
How can this be done in R?
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2003 Aug 20
1
ATA-186 locking: implausible unlock method
For those of you wanting to salvage your Cisco ATA-186 after
inadvertent locking, or after recovering your devices from a vendor
who has locked them, here is a rainy-day project for you:
http://www.sst.com/downloads/datasheet/S71077.pdf
The above document gives exact specifications on the 4mb flash EEPROM
that stores all program and configuration data on the ATA-186 (aka
Komodo.) If you
2011 Dec 27
1
rbinom
I have the following code (which I did not write) that generates
data based on a logistic model.? I'm only getting a single record
with y=1.? It seems implausible that in 50k cases that have a
single y=1.? Does that ring alarm bells for anyone else?
?
beta<-c(-1.585600,-0.246900)
betasize<-length(beta)
meanpred<-c(0,35.900000)
varpred<-c(0,1.000000)
#loop code
2010 Aug 11
1
Growth Curves with lmer
Dear all,
I have some growth curve data from an experiment that I try to fit using
lm and lmer. The curves describe the growth of classification accuracy
with the amount of training data t, so basically
y ~ 0 + t (there is no intercept because y=0 at t0)
Since the growth is somewhat nonlinear *and* in order to estimate the
treatment effect on the growth curve, the final model is
y ~ 0 + t +
2010 Jun 09
1
ordisurf (pkg vegan) gives implausible result
I'm having trouble with the ordisurf function in the vegan package.
I have created an ordination plot (cmdscale) of 60 samples based on
Bray-Curtis dissimilarities, and would like to overlay various soil edaphic
characteristics as possible clues to the clustering I observe in my plot.
However, I find that ordisurf creates a surface on the plot that is a
perfect, even gradient - and
2015 Nov 11
2
Differences from upstream RHEL
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
On 11/11/15 15:17, Edward Ned Harvey (centos) wrote:
>> From: centos-bounces at centos.org
>> [mailto:centos-bounces at centos.org] On Behalf Of Devin Reade
>>
>> The above answer is right-on. From a technical perspective, you
>> can probably expect the 3rd party software to work exactly the
>> same on RHEL and
2008 Oct 13
1
Stepwise lrm()
Hello,
I have the data set of 1 + 49 variables. One of them is binary other
are continous.
I would like to be able to fit the model with all 49 variables and
then run stepwise model selction.
I'd appriciate some code snippets...
2010 Dec 25
2
predict.lrm vs. predict.glm (with newdata)
Hi all
I have run into a case where I don't understand why predict.lrm and
predict.glm don't yield the same results. My data look like this:
set.seed(1)
library(Design); ilogit <- function(x) { 1/(1+exp(-x)) }
ORDER <- factor(sample(c("mc-sc", "sc-mc"), 403, TRUE))
CONJ <- factor(sample(c("als", "bevor", "nachdem",
2017 Sep 14
3
Help understanding why glm and lrm.fit runs with my data, but lrm does not
Dear all,
I am using the publically available GustoW dataset. The exact version I am using is available here: https://drive.google.com/open?id=0B4oZ2TQA0PAoUm85UzBFNjZ0Ulk
I would like to produce a nomogram for 5 covariates - AGE, HYP, KILLIP, HRT and ANT. I have successfully fitted a logistic regression model using the "glm" function as shown below.
library(rms)
gusto <-
2012 May 27
2
Unable to fit model using “lrm.fit”
Hi,
I am running a logistic regression model using lrm library and I get the
following error when I run the command:
mod1 <- lrm(death ~ factor(score), x=T, y=T, data = env1)
Unable to fit model using ?lrm.fit?
where score is a numeric variable from 0 to 6.
LRM executes fine for the following commands:
mod1 <- lrm(death ~ score, x=T, y=T, data = env1)
mod1<- lrm(death ~
2004 Mar 22
2
Handling of NAs in functions lrm and robcov
Hi R-helpers
I have a dataframe DF (lets say with the variables, y, x1, x2, x3, ...,
clust) containing relatively many NAs.
When I fit an ordinal regression model with the function lrm from the
Design library:
model.lrm <- lrm(y ~ x1 + x2, data=DF, x=TRUE, y=TRUE)
it will by default delete missing values in the variables y, x1, x2.
Based on model.lrm, I want to apply the robust covariance