Displaying 20 results from an estimated 10000 matches similar to: "Obtaining p-values for coefficients from LRM function (package Design) - plaintext"
2008 Dec 13
0
Obtaining p-values for coefficients from LRM function (package Design)
Dear all,
I'm using the lrm function from the package "Design", and I want to extract
the p-values from the results of that function. Given an lrm object
constructed as follows :
fit <- lrm(Y~(X1+X2+X3+X4+X5+X6+X7)^2, data=dataset)
I need the p-values for the coefficients printed by calling "fit".
fit$coef (gives a list of only the coefficients)
fit$pval, fit$p,
2008 Oct 09
2
Singular information matrix in lrm.fit
Hi R helpers,
I'm fitting large number of single factor logistic regression models
as a way to immediatly discard factor which are insignificant.
Everything works fine expect that for some factors I get error message
"Singular information matrix in lrm.fit" which breaks whole execution
loop... how to make LRM not to throw this error and simply skip
factors with singularity
2010 Jul 07
1
Different goodness of fit tests leads to contradictory conclusions
I am trying to test goodness of fit for my legalistic regression using several options as shown below.  Hosmer-Lemeshow test (whose function I borrowed from a previous post), Hosmer–le Cessie omnibus lack of fit test (also borrowed from a previous post), Pearson chi-square test, and deviance test.  All the tests, except the deviance tests, produced p-values well above 0.05.  Would anyone please
2010 Apr 26
1
Error in pf(q, df1, df2, lower.tail, log.p) : Non-numeric argument to mathematical function
inputfille
snpid	indid	genotype	gvariable	probeid	gene	geneexpression
rs1040480	CHB_NA18524	C/T	2	GI_19743926-I	PTPRT	5.850586
rs1040480	CHB_NA18526	C/C	1	GI_19743926-I	PTPRT	6.028641
rs1040480	CHB_NA18529	C/C	3	GI_19743926-I	PTPRT	5.944392
rs1040481	CHB_NA18532	C/C	1	GI_19743926-I	PTPRT	5.938578
rs1040481	CHB_NA18537	C/C	2	GI_19743926-I	PTPRT	5.874439
rs1040481	CHB_NA18540	C/C	3	GI_19743926-I
2009 Jun 23
1
How to assign fixed beta coefficients in lrm for external validation
Hi,
I am planning to externally validate a logistic prediction model in a new
cohort. Outcome is mortality. The betacoefficients were derived from a
previous published article. It seems not possible in R to assign fixed beta
coefficients to predictors like lrm (death ~
intercept+beta1*var1+beta2*var2...). How do i solve this problem?
Thank you in advance.
Joey L
-- 
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2005 Jul 12
1
Design: predict.lrm does not recognise lrm.fit object
Hello
I'm using logistic regression from the Design library (lrm), then fastbw to
undertake a backward selection and create a reduced model, before trying to
make predictions against an independent set of data using predict.lrm with
the reduced model.  I wouldn't normally use this method, but I'm
contrasting the results with an AIC/MMI approach.  The script contains:
# Determine full
2017 Sep 14
0
Help understanding why glm and lrm.fit runs with my data, but lrm does not
> On Sep 14, 2017, at 12:30 AM, Bonnett, Laura <L.J.Bonnett at liverpool.ac.uk> wrote:
> 
> 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
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
1
Help understanding why glm and lrm.fit runs with my data, but lrm does not
Fixed 'maxiter' in the help file.  Thanks.
Please give the original source of that dataset.
That dataset is a tiny sample of GUSTO-I and not large enough to fit this
model very reliably.
A nomogram using the full dataset (not publicly available to my knowledge)
is already available in http://biostat.mc.vanderbilt.edu/tmp/bbr.pdf
Use lrm, not lrm.fit for this.  Adding maxit=20 will
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
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 ~     
2010 Jun 03
1
Continous variables with implausible transformation?
Dear r users
I have a question in coding continuous variables in logistic regression.
When "rcs" is used in transforming variables, sometime it gives implausible
associations with the outcome although the model x2 is high.
So what's your tips and tricks in coding continuous variables.
P.S. How to code variables as linear+square in the formula such as lrm.
lrm(y~x+sqrt(x))
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 <-
2009 Aug 21
1
Possible bug with lrm.fit in Design Library
Hi,
I've come across a strange error when using the lrm.fit function and the 
subsequent predict function.
The model is created very quickly and can be verified by printing it on 
the console.  Everything looks good. (In fact, the performance measures 
are rather nice.)
Then, I want to use the model to predict some values.  I get the 
following error: "fit was not created by a Design
2009 Oct 25
1
Getting AIC from lrm in Design package
I am trying to obtain the AICc after performing logistic regression
using the Design package. For simplicity, I'll talk about the AIC. I
tried building a model with lrm, and then calculating the AIC as
follows:
likelihood.ratio <-
unname(lrm(succeeded~var1+var2,data=scenario,x=T,y=T)$stats["Model
L.R."]) #Model likelihood ratio???
model.params <- 2 #Num params in my model
AIC
2008 Mar 03
1
using 'lrm' for logistic regression
Hi R,
 
I am getting this error while trying to use 'lrm' function with nine
independent variables:
 
> res =
lrm(y1994~WC08301+WC08376+WC08316+WC08311+WC01001+WC08221+WC08106+WC0810
1+WC08231,data=y)
 
singular information matrix in lrm.fit (rank= 8 ).  Offending
variable(s):
WC08101 WC08221 
Error in j:(j + params[i] - 1) : NA/NaN argument
 
Now, if I take choose only four
2006 Nov 14
1
Using lrm
Hi,
I have to build a logistic regression model on a data set that I have. I
have three input variables (x1, x2, x3) and one output variable (y).
The syntax of lrm function looks like this
     lrm(formula, data, subset, na.action=na.delete, method="lrm.fit",
         model=FALSE, x=FALSE, y=FALSE, linear.predictors=TRUE, se.fit=FALSE,
         penalty=0, penalty.matrix, tol=1e-7,
  
2009 Sep 04
2
lrm in Design package--missing value where TRUE/FALSE needed
Hi,
A error message arose while I was trying to fit a ordinal model with lrm() I am using R 2.8 with Design package.
Here is a small set of mydata:
RC	RS	Sex	CovA	CovB	CovC	CovD	CovE
2	1	0	1	1	0	-0.005575280	2
2	1	0	1	0	1	-0.001959580	2
3	0	0	0	1	0	-0.004725880	2
0	0	0	1	0	0	-0.005504850	2
2	1	1	0	0	0	-0.003880170	1
2	1	0	0	1	0	-0.006074230	2
2	1	0	0	1     1 	-0.003963920	2
2	1	0	0	1	0	
2009 Aug 29
3
lrm in Design
Hello everybody,
I am trying to do a logistic regression model with lrm() from the design
package. I am comparing to groups with different medical outcome which can
either be "good" or "bad". In the help file it says that lrm codes al
responses to 0,1,2,3, etc. internally and does so in alphabetical order. I
would guess this means bad=0 and good=1.
My question: I am trying to
2006 Oct 02
1
a question regarding 'lrm'
Hi List,
I don't understand why 'lrm' doesn't recognize the '~.' formula.  I'm pretty sure it was working before. Please see below:
I'm using R2.3.0, WinXP, Design 2.0-12
thanks,
...Tao
> dat <- data.frame(y=factor(rep(1:2,each=50)), x1=rnorm(100), x2=rnorm(100), x3=rnorm(100))
> lrm(y~., data=dat, x=T, y=T)
Error in terms.formula(formula, specials =