Displaying 20 results from an estimated 9000 matches similar to: "Several questions about MCMClogit"
2008 Oct 19
1
MCMClogit: using weights
Hi everyone: I am just wondering how can I use weights with MCMClogit function (in MCMCpack package). For example, in case of glm function as given below, there is weights option in the arguments. Aparently there is no option of using weights in MCMClogit.
glm(formula, family = gaussian, data, weights, subset,
na.action, start = NULL, etastart, mustart,
offset, control =
2007 May 03
1
Bayesian logistic regression with a beta prior (MCMClogit)
Dear all,
I am trying to use the logistic regression with MCMClogit (package:
MCMCpack/Coda) and I want to put a beta prior on the parameters, but it's
giving me error message (please see output below) no matter what shape 1 or
2 I use. It works perfect with the cauchy or normal priors. Do you know if
there is a catch there somewhere? Thanks
logpriorfun <- function(beta,shape1,shape2){
2005 Jul 02
2
Is it possible to use glm() with 30 observations?
I have a very simple problem. When using glm to fit
binary logistic regression model, sometimes I receive
the following warning:
Warning messages:
1: fitted probabilities numerically 0 or 1 occurred
in: glm.fit(x = X, y = Y, weights = weights, start =
start, etastart = etastart,
2: fitted probabilities numerically 0 or 1 occurred
in: glm.fit(x = X, y = Y, weights = weights, start =
start,
2008 Apr 08
2
Metropolis acceptance rates
Is there a way to recover Metropolis-step acceptance rates AFTER
completing posterior draws?
The immediate application is in the probit.bayes and logit.bayes
models used by Zelig... which I believe is merely calling MCMCpack.
So one strategy, to which I am fixing to resort, is to call, say,
MCMClogit with verbose set to mcmc (or mcmc divided by an integer)
and then look at my screen.
2005 Aug 05
1
question regarding logit regression using glm
I got the following warning messages when I did a
binomial logit regression using glm():
Warning messages:
1: Algorithm did not converge in: glm.fit(x = X, y =
Y, weights = weights, start = start, etastart =
etastart,
2: fitted probabilities numerically 0 or 1 occurred
in: glm.fit(x = X, y = Y, weights = weights, start =
start, etastart = etastart,
Can some one share your thoughts on how to
2009 Mar 27
1
deleting/removing previous warning message in loop
Hello R Users,
I am having difficulty deleting the last warning message in a loop so that the only warning that is produced is that from the most recent line of code. I have tried options(warn=1), rm(last.warning), and resetting the last.warning using something like:
> warning("Resetting warning message")
This problem has been addressed in a previous listserve string,
2005 Jan 28
3
GLM fitting
DeaR R-useRs,
I'm trying to fit a logist model with these data:
> dati
y x
1 1 37
2 1 35
3 1 33
4 1 40
5 1 45
6 1 41
7 1 42
8 0 20
9 0 21
10 0 25
11 0 27
12 0 29
13 0 18
I use glm(), having this output:
> g<-glm(y~x,family=binomial,data=dati)
Warning messages:
1: Algorithm did not converge in: glm.fit(x = X, y =
Y, weights = weights, start = start, etastart =
2006 Jan 31
1
warnings in glm (logistic regression)
Hello R users
I ran more than 100 logistic regression analyses. Some of the analyses gave
me this kind warning below.
###########################################################
Warning messages:
1: algorithm did not converge in: glm.fit(x = X, y = Y, weights = weights,
start = start, etastart = etastart, ...
2: fitted probabilities numerically 0 or 1 occurred in: glm.fit(x = X, y =
Y,
2005 Jun 16
1
logistic regression - using polys and products of features
Hi
I can get all my features by doing this:
> logistic.model = glm(similarity ~ ., family=binomial, data =
cData[3001:3800,])
I can get the product of all my features by this:
logistic.model = glm(similarity ~ . ^ 2, family=binomial, data =
cData[3001:3800,])
I don't seem to be able to get polys by doing this:
logistic.model = glm(similarity ~ poly(.,2), family=binomial, data
2006 Jan 15
1
problems with glm
Dear R users,
I am having some problems with glm. The first is an error message "subscript out of bounds". The second is the fact that reasonable starting values are not accepted by the function.
To be more specific, here is an example:
> success <- c(13,12,11,14,14,11,13,11,12)
> failure <- c(0,0,0,0,0,0,0,2,2)
> predictor <- c(0,80*5^(0:7))
>
2007 Nov 13
2
question about glm behavior
Hello,
I was trying a glm fitting (as shown below) and I got a warning and a fitted
residual deviance larger than the null deviance. Is this the expected
behavor of glm? I would expect that even though the warning might be
warranted I should not get worse fitting with an additional covariate in the
model. Could anyone tell me what I'm missing?
I get the same results in both R2.5.1 on windows
2009 Feb 14
1
glm problem
Hello,
I have a weird problem here. What I want to do is that I need to draw 1000
samples from a matrix, and use glm on them.
when I used this command, it runs without the problem
> qdata.glm = glm(X258 ~ ., family = binomial, data =
q2data[sample(dim(q2data)[1], 1000), ])
but if I drew the sample first and run glm() on that sample, it gave a
warning.
> qdata.sample =
2005 Apr 13
1
logistic regression weights problem
Hi All,
I have a problem with weighted logistic regression. I have a number of
SNPs and a case/control scenario, but not all genotypes are as
"guaranteed" as others, so I am using weights to downsample the
importance of individuals whose genotype has been heavily "inferred".
My data is quite big, but with a dummy example:
> status <- c(1,1,1,0,0)
> SNPs <-
2003 Nov 06
1
for help about R--probit
Not real data. It was gererated randomly. The original codes are the following:
par(mfrow=c(2,1))
n <- 500
#########################
#DATA GENERATING PROCESS#
#########################
x1 <- rnorm(n,0,1)
x2 <- rchisq(n,df=3,ncp=0)-3
sigma <- 1
u1 <- rnorm(n,0,sigma)
ylatent1 <-x1+x2+u1
y1 <- (ylatent1 >=0) # create the binary indicator
#######################
#THE
2006 Feb 17
2
Something changed and glm(..., family=binomial) doesn't work now
I ran logistic regression models last week using glm
(...,family=binomial) and got a set of results. Since then I have
loaded the Epi package for ROC analysis. Now when I run those same
models I get completely different results, with most being:
Warning message:
fitted probabilities numerically 0 or 1 occurred in: glm.fit(x = X, y
= Y, weights = weights, start = start, etastart = etastart,
2002 Feb 27
1
Bug in glm.fit? (PR#1331)
G'day all,
I had a look at the GLM code of R (1.4.1) and I believe that there are
problems with the function "glm.fit" that may bite in rare
circumstances. Note, I have no data set with which I ran into
trouble. This report is solely based on having a look at the code.
Below I append a listing of the glm.fit function as produced by my
system. I have added line numbers so that I
2009 May 27
1
Warning message as a result of logistic regression performed
I am sorry if this question sounds basic but I am having trouble understanding a warning message I have been receiving in R after attempting logistic regression.
I have been using the logistic regression function in R to analyse a simulated data set. The dependent variable "failure" has an outcome of either 0 (success) or 1 (failure). Both the independent variables have been previously
2007 May 05
0
Response as matrix in MCMClogit?
I hope some of the authors of the package MCMCpack read this.
I don't know if there is a way to set the response in the model formula of
MCMClogit other than a (numeric) response vector. I think the MCMClogit in
the MCMCpack needs some development so that the response in the formula
could be set as a two-column matrix with the columns giving the numbers of
successes and failures (just as in
2011 Feb 24
2
MCMCpack combining chains
Deal all, as MCMClogit does not allow for the specification of several chains, I have run my model 3 times with different random number seeds and differently dispersed multivariate normal priors.
For example:
res1 = MCMClogit(y~x,b0=0,B0=0.001,data=mydat, burnin=500, mcmc=5500, seed=1234, thin=5)
res2 = MCMClogit(y~x,b0=1,B0=0.01,data=mydat, burnin=500, mcmc=5500, seed=5678, thin=5)
res3 =
2013 Feb 27
1
Separation issue in binary response models - glm, brglm, logistf
Dear all,
I am encountering some issues with my data and need some help.
I am trying to run glm analysis with a presence/absence variable as
response variable and several explanatory variable (time, location,
presence/absence data, abundance data).
First I tried to use the glm() function, however I was having 2 warnings
concerning glm.fit () :
# 1: glm.fit: algorithm did not converge
# 2: